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I
THE GIFT OF
1
^r
GEOLOGICAL SURVEY OF NEW JERSEY
ANNUAL REPORT
OF THS
STATE Geologist
For the Year J 906
TBBNTON, M. J,
liacOrelllBh ft Qnlgley, State Prlnten.
190T
It
CONTENTS.
Page.
'^ Board of Managers, v
Letter of Transmittai., vii
Administrative Report, i.- Administration, 3; Topographic Work, 9;
Geologic Investigations, 10 ; Awards at the Louisiana Exposition, 16.
PART I. -The Fire- Resisting Qualities of Some New Jersey Building
Stones, by W. E. McCourt, 17
PART II. -The QIass-Sand Industry of New Jersey, by Henry B. Kiim-
mel and R. B. Gage, 77
^ PART ill.— The Origin and Relations of the Newark Rocks, by J. Vol-
ney Lewis,. .^ 99
The Newark (Triassic) Copper Ores of New Jersey, by J.
* Volney Lewis, 131
Properties of Trap Rocks for Road Construction, by J.
: Volney Lewis, 165
^ PART IV.— Notes on the Minhig Industry, by Henry B. Kiammel, 173
List of Pubucations, 183
Index, 189
168543
(iii)
ILLUSTRATIONS.
PLATES.
Page.
Plates I-XXIII. — Effects of fire tests on building stones, 32-76
PtAT« XXIV. — Pumping plant—R. O. Bidwell's glass-sand pit, 85
Plate XXV.— Washing plant—R. O. Bidwell's glass-sand pit, 86
Plate XXVI. — Photomicrographs of glass sands, 87
Plate XXVII. — Photomicrographs of glass sands, 88
Plate XXVllt. — Map of the Newark (Triassic) System of New Jersey, 108
Platb XXIX. — Map of borings showing buried trap, 118
Plate XXX. — Map of location of copper mines, 135
Plate XXXI. — Fig. i. Red shale, with disseminated lenticular calcite, 148
Pig. 2. Shale with cavities filled with copper and
chalcocite, , 148
Plate XXXII. — Heave fault at old copper mine, Menlo Park, 154
FIGURES.
Figure i. — ^Areas occupied by the Newark System, 100
Figure 2. — ^Topographic map of the southwestern part of the Watchung
Mountains, iii
Figure 3. — Geologic map of the southwestern part of the Watchung
Mountains, 114
Figure 4. — Cross section on line A-B, figure 3, 115
Figure 5. — Map and section of the Griggstown Mine, 137
Figure 6. — Map of Arlington, 140
Figure 7. — Cross section at A, figure 6, Arlington, 140
Figure 8. — Map and section of the Schuyler Copper Mine, 142
Figure 9. — Diagram showing tests on trap rock as road metal, 169
(iv)
The Geological Survey of New Jersey*
BOARD OF MANAGERS.
His Excellency Edward C. Stokes, Governor and ex-oMcio Presi-
dent of the Board, Trenton.
Members at Large.
Herbert M. Lloyd, Montclair, 1907
Harrison Van Duyne, Newark, 1907
S. Bayard Dod, Orange, 1908*
John C. Smock, Trenton, 1908
Thomas W. Synnott, Wenonah, 1909
Alfred A. Woodhull, Princeton, 1909
Emmor Roberts, Moorestown, 1910
David E. Titsworth, Plainfield, 1911
George G. Tennant, Jersey City, 1911
Congressional Districts,
I. Frederick R. Brace, Blackwood, 1911
IT. P. Kennedy Reeves, Bridgeton, 1907
in. M. D. Valentine, Woodbridge, 1909
IV Washington A. Roebling, Trenton, 1908
V. FREDERICK A. Canfield, Dover, 1910
VI. George W. Wheeler, Hackensack, 1911
VII. Wendell P. Garrison, Orange, i907t
VIII. Joseph L. Munn, East Orange, 1909
IX. Joseph D. Bedle, Jersey City, 1908
X. Aaron S. Baldwin, Hoboken, 1910
State Geologist,
Henry B. Kummel.
♦Died April 19th, 1907.
t Died February 27th, 1907.
(V)
Trenton^ N. J., November 30, 1906.
To His Excellency Edward C, Stokes, Governor of the State of
New Jersey, and ex-oificio President of the Board of Man-
agers of the Geological Survey:
Sir — I have the honor to submit my Administrative Report
upon the work of the Geological Survey for the year 1906. This
will be followed by papers dealing with the Glass Sands, the
Copper Deposits and other subjects, these with the Administra-
tive Report comprising the Annual Report of the State Geologist.
It has not been possible to complete these papers so as to submit
them at this time, but the work on all of them is far advanced. I
recommend that advance copies of the Administrative Report be
printed for use of the Legislature and the printing of the whole
report be deferred until these papers can be completed. In this
,way the result of the investigations of this department may be
placed most quickly before the citizens of the State.
Yours respectfully,
Henry B. KummEL,
State Geologist,
(vii)
ADMINISTRATIVE REPORT.
Administration, Organization, Publications, Distribution,
Library, Collections, Correspondence.— Topography,
Field Work, Office Work*— Geology, Peat, Building
Stones, Trap Rock and Copffer Ores, Sands, Iron
Ores, Mineral Waters, Artesian Wells, Pleistocene
Stratigraphy, Paleozoic Stratigraphy, Paleontology^
Paleobotany* — Co-operation with the U. S* Geological
Survey* — St* Louis Exposition Medals*
I GEOI.
J
Administrative Rqx)rt*
Henry B. Kummei., State Geoi/)Gist.
A summary of the work of the Geological Survey during the
fiscal year ending October 31, 1906, is set forth in the following
pages of the Administrative Report, which, when published in
its final form, will be accompanied by several papers giving in
•detail the results of the work along particular lines.
ADMINISTRATION.
Organization, — In March, Mr. David E. Titsworth, of Plain-
field, was appointed as a member at large on the Board of
Managers to succeed Senator Ernest R. Ackerman, whose term
Tiad expired and who declined re-appointment. Messrs. Ten-
nant. Brace and Wheeler, whose terms also expired, were re-
appointed for five years.
During the year the following persons were employed upon
the Survey, the majority of them at a per diem compensation :
Henry B. Kiimmel, State Geologist.
R. B. Gage, Chemist.
Laura Lee, Clerk.
Howard M. Poland, Office assistant.
RoUin D. Salisbury, Surface Geology.
G. N. Knapp, Surface Geology and Artesian Wells.
Stuart Weller, Paleontology.
E. W. Berry, Paleobotany.
J. Volney I^ewis, Trap Rocks.
C. W. Parmelee, Peat Testing.
W. E. McCourt, Building Stones.
(3)
ANNUAL REPORT OF
C. C. Vermeule, Topographer.
P. D. Staats, Assistant Topographer.
W. A. Coriell, Draughtsman.
ly. M. Young, Topographic. assistant.
Clarence Bruen, Topographic assistant.
C. V. Coriell, Topographic assistant.
J. B. McBride, Topographic assistant.
Alma B. Roump, Stenographer.
Anabelle Lesser, Stenographer.
C. B. Hardenberg, Draughtsman.
E. J. Davis, Clerk.
Publications. — For various causes, in large part beyond the
control of the Survey, the publication of the Annual Report of
the State Geologist for 1905 (pp. 338 + X, plates XXX, figures
in text 21) was delayed and the completed volume was not
ready for distribution until the middle of October. Advance
copies, however, of the administrative report and of two scien-^
tific papers were printed early in the year and were ready for
the use of the Legislature. The completed volume contained
the following papers :
I
Administrative Report, 24 pp.
Changes Along the New Jersey Coast — Lewis M. Haupt, C. E., 70 pp.
A Brief Sketch of Fossil Plants — Edward W. Berry, 38 pp.
The Flora of the Cliff wood Clays— Edward W. Berry, 38 pp-
The Chemical Composition of the White Crystalline Limestones of
Sussex and Warren Counties — Henry B. Kiimmel, with analyses
by R. B. Gage (with map) , 16 pp^
Lake Passaic Considered as a Storage Reservoir — C. C. Vermeule
(with map), 30 pp.
A Report on the Peat Deposits of Northern Kew Jersey — C. W. Par-
melee and W. E. McCourt (with map), 86 pp.
The Mining Industry — Henry B. Kummel, 12 pp.
Three new Atlas sheets, Pluckemin, SomerviUe and New
Brunswick, on the large scale (2,000 feet per inch) were pub-
lished in May, and at once placed on sale. Twenty-four sh^s
on this scale are now completed and are being distributed as
THE STATE GEOLOGIST. 5
rapidly as orders are received. One hundred and two sheets on
this scale are necessary to cover the entire State, but the sheets
already published cover the more populous centers. There is
practically no demand for sheets of this character covering the
strictly agricultural and woodland areas, for which the maps of
the earlier series on the smaller scale amply suffice. It is doubt-
ful therefore whether it will be advisable to issue in the near
future many more sheets on the larger scale.
One sheet, No. 21, on the one-inch per mile scale, was re-
issued in August, after extensive revision of the cultural fea-
tures. This sheet, covering northern Warren and western Sus-
sex counties, replaces the old Sheet No. i, although it does not
•cover exactly the same limits.
Distribution. — ^The demand for the maps and reports issued by
the Survey is, to a certain extent, an index of the degree to which
the work of the department commends itself to the people. This
is particularly the case with respect to the maps which are not
"distributed gratuitously but are sold at 25 cents per sheet. Judged
"by this test the work is approved, since the map sales during 1966
numbered 4,581 sheets as against 3,187 for 1905 and 2,236 for
1904. It is true that the number of different sheets on sale has
increased from 37 in 1904 to 43 in 1906, but the average number
of copies sold per sheet was 60 in 1904, 80 in 1905 and 107 in
1906. There were 653 separate orders, making an average of 7
•sheets to each order. During the past year the sales of both the
one-inch maps and the large-scale sheets have increased about 50
per cent., and about 700 more copies of the latter were sold than
of the former. The unexpected increase in the demand for these
maps during the last two years has exhausted the editions of
many of the older sheets, and necessitated the printing of new
•editions. The time seemed opportune for extensive revision, so
as to bring the new editions down to date. This has been done,
although in some instances it has delayed the publication of the
maps and increased very considerably the proportion of Survey
funds needed for this work, but it has been necessary in order
to maintain the high standard of excellence for our maps estab-
lished in previous years.
6 ANNUAL REPORT OF
The total number of reports sent out during the year is set
forth in the following table, which shows a considerable falling
off over the last two years. The reason for this is found in the
fact that three reports — ^two annuals and Volume VI, the Clay
Report— were issued in 1904 and 1905. Not only were these
three reports distributed to a long mailing list, but their distribu-
tion, particularly that of Volume VI, stimulated a demand for
the previous reports. The Annual for 1905 was sent out so late
in 1906 that the demand for back reports, which is usually^
aroused by a new volume, has not yet been felt.
Below is shown in tabular form the distribution of reports and
maps for 1905 and 1906:
jgos. 1906.
Annual Report for 1905, 3,237 copies
1904, 5»279 copies 147 "
1903, 165 " 72 "
it It
tt It
It tt
tt tt
*t tt
1902, 71 " 43 "
1901, 60 " 42 "
1900, 77 " 67 "
" Reports between 1883- 1899, 775 " 570 "
Final Reports, Vol. II, 238 " 99 "^
Vol. Ill, 151 " 81 '^
Vol. IV, 136 " 85 "-
Vol. V, 175 " 89 '^
Vol. VI, 985 " 177 '*-
Other Reports, 126 " 107 **^
((
tt
((
tt
((
tt
tt
tt
Total Reports, 6,238 " 4,716
Map sheets —
Scale I inch per mile — 19 sheets, 1,245 1,974
Scale 2,000 feet per inch— 24 sheets, 1,942 2,607
Total map sheets, 3,187 4,581
Library, — The accessions to the library of the Survey during"
the year were 55 bound volumes, 119 unbound volumes, 109
pamphlets, 88 maps. The bulk of these were obtained by ex-
change.
Collections, — The geological collections of the Survey have
not been materially increased during the year, but much has been
done towards making the material on hand more accessible for
THE STATE GEOLOGIST. 7
reference. The mineral and rock specimens have been numbered,
and the labels entered in a permanent accession book. Index
cards have also been prepared for many of the specimens. Some
work has been done upon the paleontological material, but it will
be some time before all collections are properly classified. When
the work is completed there will be a list of all specimens arranged
numerically in a book, and a card index arranged by subjects
and localities. A permanent label number in paint has been placed
on each specimen, and there is no chance of the specimen becom-
ing valueless by reason of its label being lost. Mr. Poland has
performed this work under my direction as he has had time from
other duties.
There are still on hand four of the mineral collections prepared
for the use of schools of the State which are available for distri-
bution to any school, upon payment of $25.00 to cover the cost
of preparation, labelling and packing.
Correspondence, — Many letters are received containing in-
quiries of various sorts. These have a wide range, varying from
a request for the elevation above sea level of some point in the
State, or the area of some lake, questions which can be readily
answered by reference to the publications of the Survey, to more
complicated requests for advice in reference to underground
water supplies, the occurrence and chemical composition of glass
sands, peat, pure limestone and a host of other subjects. In many
instances the inquiry can be answered by sending one of the
printed reports ; in other cases it is necessary to spend considerable
time in looking up the necessary data, comparing the evidence,
and writing a letter in reply. It is the policy of the Survey to
reply to all communications as fully as possible and to furnish
the desired information whenever possible, in the belief that such
a course best brings our work into close touch with the people.
No charge is made for information of this chairacter. Not a few
of the inquiries come from, other States, and, in some cases at
least, the information furnished is believed to have resulted in
the establishment of new industries here.
Occasionally the Survey is in receipt of letters asking for in-
formation regarding New Jersey mining propositions which are
being "promoted" on the market. It is a matter of extreme
8 ANNUAL REPORT OF
difficulty to reply to these in such a way as to be absolutely fair
to all parties. It is no part of the work of the Survey to offer
advice to prospective investors (either for or against a proposi-
tion), but it is a proper function to set forth through its reports,
and in response to inquiries, geological facts known and of
record which bear upon the- case. Ordinarily, it is believed that
our duty to the investing public is done when such a reply has
been made to a direct inquiry.
It seems necessary, however, to call attention here to the
recent prospectus of a company promoting a zinc-mining proposi-
tion near Franklin Furnace, adjoining the well-known mines of
the New Jersey Zinc Company, for the reason that the work of
the State Geologist is cited in such a way as to make it appear
that this department endorses the claims set forth in the cir-
c'ular. The Geological Survey most emphatically does ,not do
this. There are no facts in its possession which warrant the
claim that zinc ore in commercial quantities occurs anywhere
in the State except in the two famous ore-bodies at Franklin
Furnace and Stirling Hill, respectively. Thousands of dol-
lars have been spent in recent years in diamond drilling on
neighboring properties in the vicinity of these ore-bodies with
negative results so far as this department knows. In all future
prospecting by this means, it should be clearly recognized by
those whose money is invested, that exploration with a diamond
drill is very expensive, costing several dollars per foot, that the
expenditure of $20,000 may be necessary to test properly a single
hole, and that the chances of locating a workable body of zinc
ore by one or two holes put down in the crystalline limestone even
in the most favorable spot are very remote.
Maps published in the Annual Reports of the State Geologist
for 1890 and for 1905 show that the property of this company is
not underlain entirely by the white limestone, as is claimed, but
in large part by the blue limestone which is highly magnesian in
character and utterly valueless for the purposes of Portland ce-
ment manufacture. White crystalline limestone, containing very
little magnesia, does, however, occur on their property but much
less extensively than the other.
The prospectus quotes parts of a report on this property writ-
ten in 1903 by Mr. Frank L. Nason, who is referred to as if he
THE STATE GEOLOGIST. 9
were a member of the State Survey when he made the report,
whereas he severed his connection with the Survey in 1 890. This
abridged report misrepresents facts and tends to mislead, but in
justice to Mr. Nason, who was an active and painstaking worker
on the Survey for a number of years, it should be stated that the
report as written by him and the report as pubHshed in the pros-
pectus, lead to very different conclusions.
EditoriaL — In addition to preparing parts of the Annual Re-
port for 1905, the manuscript of the balance was read and edited
by the State Geologist, and the entire report read both in galley
and page proof.
TOPOGRAPHIC WORK.,
Mr. C. C. Vermeule has continued to direct the topographic
work with P. D. Staats, W. A. Coriell, L. M. Young, Clarence
Bruen, C. V. Coriell and J. B. McBride as assistants for varying
periods.
Field Work, — Early in the year the revision of Sheet 21 was
commenced, and owing to the mildness of the weather it was
possible to continue the field work even during January and
February, covering 270 square miles. Some field work was found
to be necessary in connection with the proof sheets of the Pluck-
emin, Somerville, and New Brunswick sheets. Owing to altera-
tions at the County Buildings at Somerville, two bench marks of
the Survey were in danger of destruction. Temporary bench
marks were established, and on the completion of the new County
Buildings they will be transferred and made permanent. It was
not possible last year to complete the surveys in reference to the
proposed lake in the upper Passaic Valley, described at length
in the Report for 1905, so that considerable field work was neces-
sary during the early part of this year. Delay in publishing *the
Report for 1905, however, made it possible to include the results
of these studies in that report.
Office Work, — Drawings for photolithographing the Pluck-
emin, Somerville and New Brunswick sheets were completed, and
the changes on Sheet 21 were transcribed and copy made ready
for the engraver. The work of preparing a borough and town-
lo ANNUAL REPORT OF
ship map to be printed in color was completed and copy sent to
the lithographer. Drawings were made of the Lake Passaic
map. In addition to this, the proof of seven maps was read and
corrected. ^
The growing popularity of the Survey maps, as evidenced by
the increased sales, has already been alluded to. A new State
Map, on a scale of 5 miles to i inch, and corrected so as to show
the boundaries of all boroughs, townships, cities and counties,,
as they existed after the adjournment of the last Legislature, has
been prepared and will be published soon. It will be printed in
colors to make the political boundaries more prominent. The
demand for it will probably be large. It will be .Sheet No. 38,.
and will be sold at the regular price of 25 cents.
GKOI.OGIC INVESTIGATIONS.
Peat. — The laboratory determinations necessary to complete
the report upon the peat deposits kept Mr. Parmelee busy during-
the winter and spring. His conclusions were published as part
of the Annual Report for 1905, it being deemed better to delay
the completion of that volume slightly, so as to ensure prompt
publication of these results.
Building Stones, — Mr. McCourt, in continuation of the experi-
ments commenced a year ago, has made a few more tests upon the
btfilding stones of the State, to determine their fire-resisting qual-
ities. The discussion of his experiments, with illustrations show-
ing the effect of sharp changes of temperature upon his specimens,.
will be published as a paper to accompany this report.
Trap Rock and Copper Sttidies. — Mr. J. Volney Lewis has
continued his investigations of the petrography of the trap rocks,,
and the questions which bear upon the origin of the copper ores
so commonly found in the shales in close proximity to them.
The rocks of the Newark formation, including the traps, were
discussed in some detail in the Annual Reports for 1896 and
1897, but certain phases of the subject were not touched upon
at all, and others are shown by further study to be susceptible
of a different interpretation. In the last few years there has been
THE STATE GEOLOGIST. ii
a marked change in the opinion of geologists regarding the
origin of extensive formations of shale and sandstone, formerly
accepted without question as of estuarine or lacustrine origin,
but now believed more probably to be fluviatile deposits. For
som,e time the writer has felt that his discussion of this subject
in the Annual Repart for 1897 was inadequate, and should be
revised, and for this reason he is pleased to direct attention to the
alternative view outlined by Mr. Lewis in his report.
The correlation with each other of the various trap masses as
developed by Mr. Lewis is highly suggestive. Although it can
not be claimed that it rests upon so firm a basis of ascertained
facts, as do many of the other conclusions regarding these rocks,
nevertheless there is nothing inherently improbable in his con-
clusions, and much can be said in their favor. They can be ac-
cepted, therefore, as a good working hypothesis to be held until
definitely disproved.
The explanation given by the writer in the* Annual Report for
1897, for the double crest of Second Mountain with the beds of
shale in the valley, was never wholly satisfactory and was offered
with considerable hesitation, and a full comprehension of the in-
herent difficulties. The alternative hypothesis proposed by Mn
Lewis seems less beset with difficulties and it should probably re-
place the earlier view.
Regarding the origin of the copper ores, the view put forward
by Mr. Lewis that they are deposits from ascending magmatic
waters expelled from the great intrusive mass, whose separated
portions now outcrop as the Palisades, Rocky Hill, Sourland
Mountain, etc., varies distinctly from the view suggested by Dr.
W. H. Weed,* respecting the ores under the trap ridge of the
First Watchung Mountain. Owing to this differei!ce of opinion,
the facts set forth by Mr. Lewis in support of his hypothesis are
of more than ordinary interest.
Another feature of interest in his report will be found in the
tests of the resisting qualities of the trap as determined by a series
of experiments carried out by the co-operation of the Director
of the Office of Public Roads, Department of Agriculture, at
* Annual Report of the State Geologist for 1902, p. 137.
12 ANNUAL REPORT OF
Washington, D. C. Inasmuch as the trap rocks are used very
extensively for road metal, these tests of their wearing qualities
should prove of value when considered with regard to the results
already shown by actual usage. Mr. Lewis' discussion of the
petrographic features of the trap rocks will be considered in a
subsequent report.
Sands, — ^A brief paper has been prepared upon the glass sands
of the State. Chemical analyses of the New Jersey sands show
that they contain more iron than do the Pennsylvania sands
with which they come in competition, with the result that the
latter bring much better prices per ton at the glass factories.
The methods of washing the sands practiced at the pits re-
move the fine clay and silt which remain suspended in the water,
and also the grains and pebbles too large to pass a 30-mesh
sieve. Mineralogical examination of the samples of washed glass
sands collected by the Survey shows that practically all the iron
and titanium shown by chemical analyses is contained in small
grains of rutile, ilmenite, sphene and leucoxene (?). As Mr.
Gage points out in his report, if the iron-bearing minerals can
be removed by improved methods of washing, by magnetic sep-
aration, sieving, or any method which in its practical operation
is not too expensive, a grade of glass sand equal to or even
superior to the best Pennsylvania sand can readily be obtained.
When the difference in price between the Pennsylvania and the
New Jersey sand^as at present marketed is considered, the im-
portance of this point to local glass-sand miners is apparent.
Iron Ores. — During the year. Dr. W. S. Bayley, in the time
available from his other work, has continued his compilation of
data regarding the iron mines of the State. It is expected that
it will be cornpleted during the present year and be published
•early in 1908. In this connection a detailed map of the Hibemia
mines is being prepared on a large scale. The report will be ac-
companied by other maps, both of the surface and of the under-
ground workings of various mines.
Mineral Waters. — Late in the year Mr. Gage visited the min-
eral springs of the State, the waters of which are placed on the
market and have a more or less extended table use. Samples
were taken and mineral analyses will be made in the near future.
THE STATE GEOLOGIST. 13
The use of bottled spring water for drinking is increasing rap-
idly, as the surface supplies become open to suspicion through
contamination by sewage.
Artesian Wells. — ^The underground water supplies of the State
have long been a subject for study by the Survey. In many of
the Annual Reports, notably those from 1890 to 1903, records
of many artesian and other deep wells were published and some
attempts made to correlate water horizons. In 1904, Mr. G. N.
Knapp began the work of revising these records and correlating
the many samples of borings which the Survey had obtained.
This work was at first undertaken in co-operation with the Hydro-
graphic Division of the U. S. Geological Survey, and the ex-
pense was defrayed by them, in consideration of the initial work
done by the State Survey in collecting the data. For various
reasons Mr. Knapp has been delayed in the completion of the
work, and the U. S. Survey was compelled to give up further
particii>ation in it. Since August ist the work has been carried
on at the expense of the State Survey, and the report will be
completed by the end of December.
It is proper here to state that the U. S. Geological Survey in
ceasing to co-operate further in this investigation freely waived
all claims to any part of the results already reached.
Stratigraphy. Pleistocene. — The interpretation and mapping
of the surface sands and gravels of southern New Jersey have
engaged the attention of the State S^urvey under Mr. Salisbury
and his assistants portions of each year since 1892. Similar de-
posits in States further south were studied by other workers, and
results were reached by them which did not harmonize with those
put forth by this department. When the southern interpretation
was carried northward and applied to deposits on the west side of
the Delaware, and then extended into New Jersey, the differences
in view were emphasized and tne necessity for a modification in
some direction was apparent. This was thie more necessary since
the U. S. Geological Survey is publishing a geological atlas of the
whole country, and is working in co-operation with the New
Jersey Survey as well as with some other State surveys in their
respective States.
14 ANNUAL REPORT OF
In June a field conference was held in New Jersey) in which
Messrs. C. W. Hayes and Benjamin L. Miller, of the U. S.
Geological Survey, and R. D. Salisbury and G. N. Knapp, of the
New Jersey Survey, together with the State Geologist, took part.
The deposits on both sides of the Delaware river were examined
with maps in hand which represented the diverse views. The
resiilt of the conference was the acceptance of the interpretation
and the mapping urged by the workers on the New Jersey Survey,
and the decision to bring the Pennsylvania work into harmony
with it. Some changes in the details of our mapping, in part
because of clerical .errors in transcribing the maps, were sug-
gested and agreed to, but the subdivisions advocated and the
interpretation put upon the deposits by the New Jersey Stirvey
were accepted as correct by Mr. Hayes for the National Survey.
This decision removes one of the causes of the long delay in
publishing the geologic atlases of the southern part of the State.
Upon the termination of this conference, Mr. Knapp took up
and by the end of July completed his maps and manuscript upon
these formations. The final report will now be prepared for
publication by Mr. Salisbury, and will be a companion volume to
his Report upon the Glacial Geology, which was published in
1902 as Volume V.
Stratigraphy. Paleozoic. — ^The structural relations of the
limestones and shales of Warren county present some interesting
features which were the subject of careful examination during a
few days in July by the State Geologist. The normal Paleozoic
succession in the Kittatinny valley is as follows, from the top
downward :
Hudson shales and slates, thickness great.
Trenton limestones (essentially non-magnesian), 100-200 feet.
Kittatinny limestone (mostly magnesian), thickness probably
about 3,000 feet.
Hardyston quartzite, 20-150 feet.
This succession can usually be traced in making a cross-section
from the crystalline Highlands to the Kittatinny Mountain, which
is com.posed of the Shawangunk conglomerate (more frequently
called Oneida conglomerate, but recently determined by the New
York Survey to be Salina in age). In the vicinity of Hope,
THE STATE GEOLOGIST. 15
Johnsonburg and the northern end of Jenny Jump Mountain,
however, the structure is very compHcated and the relations of
the rocks can be determined with difficulty. Areas of the Kitta-
tinny limestone of varying size occur surrounded entirely by the
Hudson slate, while the Trenton Hmestone, which should occur
between them, is entirely absent. That these are not simply
eroded anticlinal folds showing the older rocks in the center
surrounded by younger beds is shown both by the absence of the
Trenton formation and by the inclination of the strata which do
not possess the anticlinal structure. That the region has been
greatly faulted is evident even upon cursory examination, but
data to determine the exact nature and position of the fault
planes, as well as the direction and amount of thrust, are not easy
to find. It seems demonstrable, however, that in the folding
which occurred in this region the limestone was thrust horizon-
tally over the shale from southeast to northwest for a consider-
able distance. Later in the folding the thrust plane itself became
somewhat folded, being depressed in troughs and rising in broad
gentle arches. Subsequent erosion has removed hundreds of
feet of sediment. Where the thrust plane was depressed so as to
be still below the limit to which erosion has now progressed, that
is below the present surface, the overthrust beds of limestone are
found upon the slate. Where the thrust plane was slightly arched
the limestones have been removed, and the present surface is in
the shales below the thrust.
This explanation makes clear also the presence of several small
areas of crystalline rocks, the occurrence of which within the
limestone and slate areas far removed from the gfreat mass of
gneisses and gfranites, is not readily explained on other hypoth-
eses. They are not intrusives in the sedimentary rocks, nor are
they normal exposures of the underlying crystallines revealed by
deep erosion. On the contrary, like the limestone areas above re-
ferred to, they are remnants of the basal rocks which in the fold-
ing were thrust horizontally over and upon the much later sedi-
ments.
Paleontology, — ^Dr. Weller has almost completed his studies of
the fossils found in the sands, clays and marls of the Cretaceous
strata, and the report will soon be ready for publication. It will
i6 ANNUAL REPORT OF STATE GEOLOGIST.
add miich to our knowledge of the life of this period, and will be
a valuable contribution to the Paleontology of New Jersey. Ow-
ing to its purely technical character, only a small edition will be
printed, and its distribution will be limited.
Paleobotany. — ^A small allotment was made Mr. E. W. Berry
in connection with like sums from the Maryland Survey and the
National Survey to enable him to continue his studies of the
fossil plants of the Coastal Plain, the money contributed by this
department being spent only in New Jersey.
Co-operation with the U. S. Geological Survey, — As already
indicated, a field conference has been held with representatives of
the U. S. Geological Survey, as provided by the agreement made
in 1904*, at which the interpretation of the non-glacial Pleisto-
cene deposits of the southern counties, urged by Messrs. Salis-
bury and Knapp, of the State Survey, were accepted for use in
the geologic atlas. This, of course, involved the rejection of the
opposing view, and will necessitate, the re-mapping by the U. S-
geologists of the same formations on the Pennsylvania side of the
Delaware River to bring them into accord with the New Jersey
work. It is hoped that, as soon as this is done, the maps of this
region can be issued without further delay.
In June the manuscript descriptive of the Paleozoic sediments
on the Franklin Furnace quadrangle was prepared and sent to
Washington. The State's share of this work has now been com-
pleted. The manuscript of three other quadrangles is in various
stages of preparation, but it is difficult to say when the conv
pleted maps will be issued.
Awards at the Louisiana Purchase Exposition. — ^During the
year the Geological Survey received the medals indicative of the
awards made to it for its display at the St. Louis Exposition in
1904. A grand prize was received for the maps and models;
four gold medals for the exhibits of clays, rcfcks and minerals,
fossil restorations and collective exhibit respectively, and a silver
medal for a museum petrographic microscope. The medals are
all of bronze metal, but the various grades are distinguished by
their shape and by slight differences in design.
♦Annual Report of the State Geologist for 1904, p. 15.
PART L
The Firc-Rcsisting Qualities of Some
New Jersey Building Stones*
By W. E. McCOURT.
2 GEOL (17)
The Fire-Resisting Qualities of Some New
Jersey Building Stones.
BY W. E. MCCOURT.
OUTLINE.
Introduction.
Earlier investigations.
Observations in burned buildings.
Method of making the fire tests.
Samples tested.
General summary of results.
Granites and Gneisses.
Diabases.
Sandstones.
Limestones.
Argillite.
Detailed statement of experiments, with illustrations.
INTRODUCTION.
In order to determine the durability of a building stone a
number of tests are performed on it. Certain tests are, in cer-
tain cases, more important than others, though all are desira-
ble in order to get at the relative merits of building stones.
There is one test which has often been neglected, and this is the
effect of extreme heat. This is of much importance in some
cases, especially when the stone is to be used in a location where
a conflagration is apt to occur.
Accordingly, a number of samples of New Jersey stones were
collected by the writer during the summers of 1904 and 1905,
under the direction of the State Geologist, and these were tested
in the Geological Laboratory of Cornell University, in connec-
tion with work for an advanced degree. The object of this
(19)
20 THE STATE GEOLOGIST.
investigation was to ascertain the relative ability of the various
stones to withstand extremie heat, and to determine, as far as
possible, the criteria which control the refractive ability.
The writer wishes to express his appreciation of the courtesies
extended to him by the various laborers, superintendents and
owners at the quarries visited. Thanks are due to many, but
special mention is due Mr. W. J. Ledger, of the S. B. Twinning
Co., Mr. Merriman, resident engineer at the Boonton Dam, Mr.
George Sweezy, of the Federal Hill Granite Co. and Mr. Her-
bert K. Salmon, of the North Jersey Stone Co. To Dr. A. C.
Gill, of Cornell University, acknowledgment is due for help
in the petrographic descriptions of the samples, and to Dr. Hein-
rich Ries, of Cornell University, for general criticism of the
entire work. Most of the photographs for this paper were-
taken by Mr. G. F. Morgan, of Ithaca.
EARUER INVESTIGATIONS.
Investigations of the refractoriness of building stones are
comparatively few. Cutting^ was the first to perform any ex-
tensive tests and from his results he came to the conclusion that
the various stones for building purposes withstand extreme heat
in the following order : Marble, limestone, sandstone, and gran-
ite, but all were injured to some extent.
Buckley^ carried on a series of tests on Wisconsin and Mis-
souri building stones, and came to the conclusion that a stone
with a simple mineralogical composition, and a uniform texture
has the greatest capacity to withstand high heat. According to
him, limestones, up to the point of calcination, acted best of all
the stones, but beyond that point they flaked off at the comers.
The grajiites all cracked, though in varying degrees, the coarser
grained ones suffering the greatest injury, while the sandstone
showed little outward evidence of damage, but most of them
could be crumbled in the hand.
* Weekly Underwriter, XXIII, 42, 1880. Ibid XXII, 257, 287, 304, 1880.
* Wis. Geol. & Nat. Hist. Sur. Bull. IV, 7i & 385, 1898. Mo. Bur. of Geo!.
& Mines, II, 2nd series 50, 1904.
FIRE TESTS ON BUILDING STONES. 21
The consensus of opinion seems to be that granites are the least
refractory of the building stones. The limestones and marble
calcine and flake off at a high heat, while some of the sand-
stones stand up well, and others are reduced to sand.
OBSERVATIONS IN BURNED BUII.DINGS.
The literature of the effect of fires on the various kinds of
stone was studied to see if any facts might be deduced, but we
cannot safely draw any definite conclusions, since the actual con-
ditions in a fire are varied, and there have never been any de-
tailed or accurate observations made at the time of the confla-
gration. However, it is of interest to note that in an intense
fire all stones are injured to some extent, especially where the
stonework is thin or exposed. Until accurate observations of
the different conditions of exposure, amount of heat, etc., in a
conflagration are made, we cannot safely draw any conclusions
from this source as to the relative refractoriness of the different
building stones.
METHOD O^ MAKING ]?IRE TESTS.
In the tests to be described 3-inch cubes were used. All
Other investigators have employed smaller cubes, but these do
not give so accurate results as those of a larger dimension.
When a larger cube is heated, the heat penetrates only a slight
distance into the body, while the interior may remain compara-
tively cold. Upon cooling there are set up differential stresses
which would not be caused in a small sample of the stone.
Tests have been made on larger and smaller cubes of the same
kind of stone, and invariably the small pieces stood the heat
much better than the larger cube. Naturally, then, the large
cube should always be used, as this approximates more closely
conditions which prevail in buildings.
As far as possible six tests were made on the stone from each
locality. Four of these tests were made in a Seger gas-furnace,
which allowed the cube to be gradually and evenly heated. In
22 THE STATE GEOLOGIST.
the cover of the ■ furnace an opening was cut large enough to
admit the specimen, to which a wire had been fastened in order
to facihtate handling. Two flame tests were carried on, and for
these an ordinary blast lamp was made use of.
In the furnace tests one sample was heated at a time. After
the cube had been placed in the furnace the heat, measured by a
thermo-electric pyrometer, was applied gradually for half an
hour untif a temperature of 550° C. (i022°P) was reached.
This degree of heat was maintained for half an hour, and at the
end of that time the sample was removed from the furnace and
allowed to cool in the air. The second cube was heated like the
first, but this was suddenly cooled by the application of a strong
stream of water. The third and fourth samples were heated
to 850"^ C. (1562°), kept at that temperature for half an hour
and then cooled, one slowly and the other suddenly, as the tests
at 550° C.
In the first flame test the cube was so placed as to be enveloped
on three sides by a steady but not strong gas blast. The flame
was allowed to play on the cube for 10 minutes, then the sample
was allowed to cool for five minutes, at the end of which time
the flame was again applied for 10 minutes and the cube was
again allowed to cool. The second flame test was carried 011
somewhat similarly to the first test, but in this case a strong
stream of water was applied, along with the flame, for five min-
utes after the cube has been subjected to the flame alone for 10
minutes. The water was turned off and the flame allowed to
act on the cube for another five minutes, after which, for five
minutes more, the flame and water together acted on the sample.
sampi,e:s tested.
Samples tested were obtained from the following localities :
FIRE TESTS ON BUILDING STONES.
23
LOCALITY.
COUNTY.
COMPANY.
Plate
Reference.
GRANITES AND GNEISSES.
German Valley, i mile
northwest,
Cranberry Lake, 2 miles
south,
Cranberry Lake,
Montville, i mile north,.
Pompton Junction,
Dover,
Mt. Arlington
Waterloo,
Hibernia, 3 miles north-
west,
Morristown, i mile west,
Plainfield, i mile west,..
Lambertville,
Wilburtha,
Stockton,
Raven Rock
Martinsville, Yi mile
south,
Pleasantdale,
Avondale,
Morris,
Sussex,
Sussex,
Morris,
Passaic,
Morris,
Morris,
Morris,
Morris,
Morris,
Lyman Kice,
North Jersey Stone Co.,.
Panther Hill Granite Co.,
Jersey City Water Sup-
ply Co.,
Federal Hill Granite Co.,
Thomas Fanning,
North Jersey Stone Co.,.
North Jersey Stone Co.,.
P. Lubey,
DIABASES.
Somerset, . . F. W. Wilson & C6., . . .
Hunterdon,. B. M. & J. S. Shanley, . .
SANDSTONES.
Avondale,
North Arlington,
Closter, 2 miles east,
Frankim Furnace,
Newton,
Phillipsburg,
Mercer
Hunterdon, .
Hunterdon, .
Somerset, ..
Essex,
Essex,
Essex, .
Hudson,
Bergen,
De Graves Bros.,
S. B. Twinning Co.,
Stockton Stone Co.,
W. E. Bartle,
F. W. Shrump,
Belleville Quarry and
Stone Co.,
Belleville Quarry and
Stone Co.,
Geo. Bayliss,
J. Gamble & Son,
LIMESTONES.
Sussex,
Sussex,
Warren, . . .
Nicol Limestone Co.,
0*Donnel & McManiman,
ARGIIXITE ROCK.
Princeton, i mile north,. ( Mercer I Margerum Bros.,
I.
n.
H.
HL
IV.
V.
VL
vn.
VHL
IX.
X.
XI.
xn.
xin.
XIV.
XV.
XVI.
XVII.
XVII.
XVIII.
XIX.
XX.
XXI.
XXIL
XXIIL
RESULTS OF THE TESTS.
General Summary. — The crystallines, at a temperature of 550°
C. (1022° F.) were not greatly affected, and the cracks which
were developed were but slight. The gneisses, as a rule, cracked
parallel to the banding, and as a general thing it is fairly safe
24 THE STATE GEOLOGIST.
to say that a gneiss will be more damaged than a crystalline
rock of the same texture and similar mineralogical composition
without the banding. The sample of clay rock from Princeton
acted badly. Clay rocks usually suffer much damage in a fire.
Well known examples of this are seen in the splintering and
shivering into fragments of the roofing slates and those used on
staircases. The sandstones, as a whole, resisted well at the lower
temperature, while the limestones seem to have suffered the least
. injury of all the stones tested at 550°.
The degree of heat which is reached in a conflagration un-
doubtedly exceeds 550° C, but outside of the severe part of the
fire there would be buildings subjected to a temperature of
550° or thereabouts. The stones in such buildings would prob-
ably suffer very little injury. Limestones would act best, pro-
vided the point of calcination had not been reached. Sand-
stones would follow limestones in their ability to resist the
damage from the heating. To be sure, this series of tests has
shown that some of these New Jersey samples cracked, but the
cracks are slight, and in most cases parallel to the planes of bed-
ding. This damage would not materially affect the stability of
the structure if the stones had been properly set on their beds.
Fine-grained crystallines would follow sandstones, and last would
come the coarser crystallines.
When we approach a heat equal to 850° C. (1562° P.) we ap-
proximate fairly well the probable degree of heat which is
reached in a conflagration. In this series of experiments the
crystallines, as a class, acted badly, though some samples gave
better results. In the case of the igneous rocks the main factor
controlling the refractoriness seems to be the texture. The finer,-
grained varieties act much better than the coarser ones. In the
stones of the fine texture the cracks are small and quite regular,
with a tendency to split off the corners, whereas in the stones ot
coarser texture the cracks are irregular and open, and in some
cases they were so bad as to cause the cube to crumble. The
gneisses would suffer great injury and the amount of damage
would be largely controlled by variations in texture and the
amount and style of banding. Those stones in which there are
seams of coarser material will crack considerably more than the
FIRE TESTS ON BUILDING STONES. 25
even-grained varieties, and the much banded gneiss will tend to
split more readily, especially in a direction parallel to the banding.
Naturally the sandstones vary somewhat in their ability to
withstand the effect of this extreme heat. Here the controlling
factors seemed to be texture, composition, kind of cementing
material and manner of cementation. The coarser-grained
stones and those made up of various mineral constituents suffered
worse than the finer-grained and more simple ones. It is to be
inferred that a compact stone will suffer less than one in which
there are a number of pore spaces. The greater the percentage
of porosity, in general, the greater will be the damage. A very
porous stone will be reduced to sand, while a dense one will
behave quite creditably. A coarse stone will crack irregularly,
while a finer-grained one will split more regularly and in most
cases in a direction parallel to the lamination planes. A sand-
stone which has a cement of limonite or one in which there is a
large percentage of clay will crack more readily than one in
which silica or calcite bind the grains together, for the reason
that the water is driven off from. the clay and limonite, and as a
consequence greater stresses are set up in the stone.
The limestones, at the higher temperature, because of the fact
that the calcination point has been reached, flaked and in some
cases went to pieces. A pure limestone suffered greater injury
than the impure or dolomitic samples.
The results of the flame tests cannot be considered as indicative
of the probable effect of a fire on the body of the stone in a
structure, but, more correctly, may be considered as a probable
indication of the effect on thin edges of stone, such as lintels,
pillars, projecting comers, carving, etc. All the classes were
injured in these tests. The degree of heat reached in these
experiments did not exceed 700° C, so it is safe to say that all
thin edges of stone would suffer in a conflagration, possibly
so much so as to need repairing. The tendency seemed to have
been for the cubes to split off in shells around the point of great-
est attack. This concentric peeling is seen in nature in the
exfoliation of granite or other rocks in regions where there are
decided changes in temperature, especially between the day and
night. It has also been observed in buildings which were
26 THE STATE GEOLOGIST.
located in the burned districts of Paterson, Baltimore and San
Francisco.
At a temperature, then, which is probable in a fire, the finer-
grained and more compact the stone and the simpler in mineral
composition the better will it be able to resist the damaging
effect of extreme heat. The sudden cooling by a stream of
water will cause more injury than the slow cooling. Many of
the samples assumed a brownish tinge upon being heated, due
to a change of the iron present in the stone, from a ferrous to a
ferric state.
If the temperature does not exceed 550° C. all the building
stones tested in this series will be little damaged, and they will
resist injury in this order: limestone, sandstone, fine-grained
crystallines, coarse-grained crystallines and clay rocks, the first
being most resistant. If, however, the temperature be higher, all
thin edges of stone work will suffer and the various stones tested
in this set of experiments will resist in the following order, the
first on the list offering the greatest resistance to injury; fine-
grained compact sandstones, medium-grained dense sandstone,
fine-textured granites, fine-grained gneisses, iinpure limestone,
loose sandstone, coarse granite, coarse gneiss, clay rocks and
pure limestone.
Granites and Gneisses. — But two samples remained apparently
unaffected after 550° C. slow-cooling test, those from Mont-
ville and Waterloo (Plates III. and' VII.) The others suffered
some, though very slight, injury. The cubes from Pompton
Junction and Morristown show only a number of minute cracks
on the polished surfaces, which do not seem to have weakened
the stones. The small crack in the Dover sample (Plate V.) is
in the coarser texture. All the other cubes tested at this temper-
ature developed some small cracks. Those from German Val-
ley, Montville, Mt. Arlington and Morristown were changed in
color to a brown tinge, due, probably to a change in the con--
dition of the iron present in the stones. Usually, on fast cooling,
a stone is more damaged than on slow cooling at the same tem-
perature, but the two samples of gneiss from Cranberry Lake
remained uninjured upon fast cooling, but were cracked some-
what in the slow-cooling test. Upon fast cooling, at 550° C. all
FIRE TESTS ON BUILDING STONES. 27
the other cubes suffered some injury, though it was still slight ;
the only severe case being the stone from Morristown, which
had one bad crack extending around three sides of the cube.
Upon slow cooling, at 850° C. we found that the damage was
still worse, though in some cases yet comparatively slight. The
sample of gneiss from Pompton Junction, which was the coars-
est stone tested, was badly and irregularly cracked and lost some
of its particles in the test (Plate IV). The Mt. Arlington and
Waterloo samples developed a number of small cracks, and the
latter looked' as if a blow would crumble it. The German Valley
cube developed one open crack almost around the sample and the
stone from Montville showed a number of small cracks. The
cubes from Dover and Morristown were badly damaged, but in
these cases the cracks were largely in the coarser seams. In the
latter sample there was also a larger piece broken off one edge.
Upon fast cooling at 850° C. we found that here, as in most cases
in the 550° C. tests, the fast-cooled cubes were more injured than
the slow-cooled ones, and all at this temperature in a fire, if
cooled quickly by a stream of water would probably suffer great
injury. The cube from Pompton Junction crumbled, those from
German Valley and Montville were badly and irregularly cracked
and lost some small spalls. Here, again, the cracks in those
stones of varying textures seem to be more or less limited to the
coarser seams.
All the samples were injured by the action of the flame, though
in varying degrees. The cube from Montville (Plate III.) was
broken into two pieces; the Mt. Arlington sample was broken
into a number of pieces (Plate VI.) and all the others, as can be
seen by reference to the plates, lost pieces from the corners, and in
all cases show some cracks, the Pompton Junction samples being
badly cracked. Under the combined action of the flame and
water, the Morristown sample lost a smaller piece from the at-
tacked comer than in the flame test, but it was considerably
more cracked. All the cubes suffered, both by losing pieces from
the corners and by being cracked. The stones from German
Valley, Dover, Mt. Arlington and Waterloo look as if a blow
would easily crumble them.
28 THE STATE GEOLOGIST.
Judging* from these tests, most of these stones would stand a
low heat quite well, especially if not cooled by a stream of water.
At a higher heat, however, they would probably act badly, and
if exposed in corners, on window sills and the like, they would
suffer great injury. The finer-grained stones seem to stand up
better than the coarser ones and in those stones in which there is
a variation of texture the cracking seems to be greater and more
severe, especially in the coarser seams. The cracking in the
gneiss has a tendency to follow the banding, though this- is not
a definite rule. A polished surface will show minute cracks, not
noticeable on an unpolished face.
Diabase, — Two samples of diabase were tested, a fine-grained
variety from Plainfield and a medium-grained one from Lam-
bertville; but we cannot compare these two, inasmuch as the
Plainfield stone contains a number of calcite spherules, which
very materially affected the behavior of the stone in the tests.
It would be interesting to test a sample of this finer-grained stone
containing no calcite. Then we could determine more definitely
the factors controlling the refractoriness, for the composition,
both mineralogical and chemical, would be practically the same
and we would have only the difference in texture as a variable
factor.
In the 550° C. slow-cooling test the sample from Lambertville
developed one slight crack around two sides. In the fast-cool-
ing test, at this same temperature, the cracking was a trifle more
marked, extending around three sides. The cube from Plain-
field took on a brown tinge and developed several cracks.
At 850° C. the Lambertville stone was little affected, showing
only several very small cracks, but the cube from Plainfield was
broken into numerous small pieces, due, probably, to the calcite
giving off carbon dioxide in changing to CaO, and thus exerting
a breaking pressure. In the rapidly cooled cube a similar re-
sult was brought about, while the sample from Lambertville
developed several cracks, one of which was opened and showed
on three sides.
Under the flame the Plainfield stone spalled somewhat on the
exposed surfaces and developed one crack, while the Lambert-
ville cube lost a one-inch piece from the corner and was slightly
FIRE TESTS ON BUILDING STONES. 29
cracked. Under the flame and water test the damage was, in
bath cases, greater, larger pieces being broken from the corners
and more cracks developed.
Sandstones. — ^Among the sandstones there is much variation
in the capacity of the different samples to resist the effect of ex-
treme heat. Some seemed little affected, while others were badly
injured.
Some of the cubes, Pleasantdale ( Plate XVI ) , Avondale ( Plate
XVII), North Arlington (Plate XVIII), and Closter (Plate
XIX), remained uninjured on slow cooling, after having been
heated to 550° C. On fast cooling the Pleasantdale and North
Arlington samples developed slight cracks, while the cube from
Closter still remained unaffected. A coarse variety of stone
from Afvondale (Plate XVII), was uninjured by the sud-
den cooling. The stones from Martinsville and North Arling-
ton took on a brownish tinge because of the change in the condi-
tion of the iron present. All the other samples showed some
injury, though only slight, both on slow and sudden cooling,
and in most all cases the cracks in the samples were parallel to
the planes of lamination.
In the 850° C. tests all of the stones were injured, though in
varying degrees. The most pronounced cracks, in all cases, are
along the bedding planes, though many of the stones also
show transverse cracks. The samples from Stockton (Plate
XIII) and Martinsville (Plate XV) were quite badly injured
on slow cooling, and more so on fast cooling. Thfe cubes from
Wilburtha (Plate XII), Avondale (Plate XVII) and
Closter (Plate XIX) suffered much injury on rapid cooling.
The sample from Pleasantdale (Plate XVI) came through the
flame test with only slight cracks, and the Martinsville (Plate
XV) and Closter (Plate XIX] cubes had but small pieces
broken off from the comers. The others were much impaired.
Under the action of the flame and water, the stone from
Closter (Plate XIX) remained unchanged, but all the others
had large pieces broken from the comers, and except those from
Raven Rock (Plate XIV) and Martinsville (Plate XV), showed
many cracks in addition.
3Q THE STATE GEOLOGIST.
. Limestones, — In both of the 550° C. tests all of the cubes re-
mained apparently unchanged, except the sample from Phillips-
burg, which developed several small cracks when cooled quickly.
In the 850° C. series all the cubes were injured to a greater or
le&s extent. The Franklin Furnace stone was badly injured, so
much so as to make it worthless at this temperature (Plate XX).
The cube from Phillipsburg developed some bad cracks, espec-
ially along the veins of calcite, while the Newton sample stood
the test fairly well. The Franklin Furnace stone was thor-
oughly calcined on the outside, while the two other stones were
little calcined, due to the impurity of the samples.
In the flame tests all lost pieces from the attacked comer, be-
sides showing several cracks in each case, the Newton cube
suffering the greatest injury by being broken into several pieces.
Under the action of the flame and water the injury was still
greater, all of the samples being so broken as to render them
useless.
We see, then, that the limestones will stand up very well at
550° C. ;: at 850° C. the coarser and more pure seem to have suf-
fered the greater injury, and the sample ribbed with veins of cal-
cite was injured more than the one with no such veins. All acted
quite badly under the flame, and more so under the flame and
water.
Argillite. — This sample is an extremely fine-grained rock from
Princeton, much like a shale, but which contains an abundance of
calcareous material.
Upon slow cooling, after having been heated to 550° C the
cube was split along the bedding, besides showing other parallel
cracks (Plate XXIII). Upon fast cooling some transverse
cracks were developed, but most of the bad cracks extend par-
allel to the lamination planes.
The flame test developed one slight crack along the bed and
around three sides, while the flame and water together broke a
small piece off the upper edge, besides cracking the sample
around three sides along the bed.
Plates and Detailed Description of Tests.
(30
Plate I.
Syenite, ]?rom Quarry o^ Lyman Kice, German Vali^ey,
Morris County.
This is a medium-grained greenish stone used for building
purposes. It is made up largely of feldspar, with much green
augite and some quartz. Under the microscope, the feldspar,
which is very fresh, appears to be mostly microperthite and some
plagioclase. The green augite and quartz make up the remain-
der, with the exception of a few good crystals of zircon, some
rounded apatites and a few magnetite grains.
Fire Tests. ^ In all of the tests this sample suffered some in-
jury, quite noticeable in the 850° C. tests, especially in the rapidly
cooled tube, where the stone was very badly cracked. Under the
action of the flame the injury was slight as compared to that of
the flame and water test. In most cases the stone was discolored.
No. 35. 550** slow-cooling test. No. 36. sso** fast-cooling test.
No. 34. 850° slow-cooling test. No. ZJ- 850° fast-cooling test.
No. 176. Flame test. No. 145. Flame and water test.
' In all tests, the temperatures cited are Centigrade not Fahrenheit.
(32)
Geological Survey, igo6.
Syenite. German Valley, Morris County.
Plate II.
Nos. 6y, 68, 177, 146. Gneiss from North Jersey Stone
Company's Quarry, Cranberry Lake, Sussex County.
This is a light-grey stone made up of light feldspar and
quartz, with numerous small garnets scattered through the body.
The quartz is less abundant than the feldspar, of which an acid
plagioclase is the principal species, although orthoclase and
some microcline microperthite are also present. The microscope
also revealed the presence of some scales of biotite, which, in
places had been bleached and in others had been altered to epidote.
Some garnets and one zircon crystal were also noted in the
section.
Fire Tests. At 550° C. the stone acted well, the fast-cooled
cube being apparently uninjured, while the slowly cooled sample
showed but one small crack on one side. No samples were tested
at 850° C. In the flame test the stone lost some small pieces and
in the flame and water test it was damaged to a slightly greater
extent.
No. ^. 550'' slow-cooling test. No. 68. 550° fast-cooling test.
No. 177. Flame test. No. 146. Flame and water test.
Nos. 58, 59. Gneiss ^rom Panther Hill Granite Com-
pany's Quarry, Cranberry Lake, Sussex County.
The stone from this quarry, which, is used as a building stone,
has a grey color and shows a good gneissic structure. Feldspar
is more abundant than quartz, and the darker minerals evident in
the hand specimen are hornblende and augite. The microscope
showed the presence of much sphene. The green augite is more
3 GEOL
abundant than the green hornblende, to which it has altered in
places. The quartz is less abundant than the feldspar, which
is mostly an intergrowth of very acid plagioclase, some micro-
cline and microcline microperthite. Rounded apatites are not
rare and one scale of muscovite was noted in the section.
Fire Tests. Only two tests were made on this stone, both at
550^ C, in which the samples seem to have been little damaged.
Upon slow cooling the cube showed one small crack at one
corner, but not bad enough to seriously injure it. This stone,
like many of the others, took on a brownish tinge.
No. 58. 550° slow-cooling test. No. 59. 550'' fast-cooling test.
(34)
Geological Survey 1906.
Gneisses. Cranberry Lake, Sussex County.
PI.ATE III.
Gneiss ]?rom the Jersey City Water Suppi^y Company's
Quarry, Montvii^le, Morris County.
The stone from this locality is very variable, both in texture
and mineral composition. The coarser-grained kind is made
up entirely of quartz and feldspar and some of the crystals are
over one-half inch in size. The samples which were tested are
medium grained and of a dark-grey color, composed of feldspar,
quartz and some biotite. The stone was quarried only for use
in the construction of the Boonton Dam.
Fire Tests. Upon slow cooling at 550° C. the cube remained
intact, and but a few small cracks were developed on rapid cool-
ing. All these samples were changed in color to the brown, so
characteristic of many of the stones. At 850° C. the samples were
irregularly cracked, the fast-cooled cube slightly more so than
the slowly cooled one. For the most part the cracks are par-
allel to the gneissic banding. Under the flame the cube split
into two large pieces, besides losing a small piece from the ex-
posed comer, and while it did not break into two pieces under
the action of the flame and water, it was considerably cracked
and lost several small pieces.
No. 84. 550'' slow-cooling test.
No. 85. 550** fast-cooling test.
No. 86. 850° sjow-cooling test.
No. 87. 850° fast-cooling test.
No. 178. Flame test.
No. 147. Flame and water test.
(3&)
Geological Survey, igo6.
Gneiss. Montville, Morris County,
PI.ATE IV.
Granite-Gneiss from Federai^ Hii.Iv Granite Company's
Quarry^ Pompton Junction^ Passaic County.
This is a pinkish stone which is used for general building pur-
poses. It is very coarse-grained, some of the crystals having a
size of over three-quarters of an inch; pink feldspar, smoky
quartz and green hornblende are easily distinguished in the hand
specimen. In some places the hornblende has weathered, thus
giving a green stain to the stone.
Fire Tests. This coarse-grained stone was little damaged in
the 550^ C. tests. The slowly cooled cube developed some minute
cracks on the polished face, more especially in the feldspars,
which is due, probably, to the cleaveage. The fast-cooled sample
shows several small, irregular cracks around the grains, not
enough, however, to materially weaken the stone. In the 850° C.
experiments the samples acted badly, the slowly cooled cube was
considerably cracked and the fast-cooled one was so damaged as
to cause the stone to crumble. This is probably due to the ex-
treme coarseness of the grain. In the two flame tests the sam-
ples lost small pieces from the exposed corners.
No. 205. 550** slow-cooling test.
No. 207. 850° slow-cooling test.
No. 209. Flame test.
No. 206. 550** fast-cooling test.
No. 208 850** fast-cooling test.
No. 210. Flame and water test.
(3S)
Geological Survey, igo6.
itic Gneiss, Pompton Junction, Passaic County.
• fe*
PI.ATE V.
Gneiss from Thomas Fanning^s Quarry, Dover, Morris
County.
This is a greenish stone used for structural work, of uneven,
though prevailingly medium, texture and of irregular composi-
tion. However, in the samples tested, quartz, feldspar and
hornblende could be distinguished.
Fire Tests. This stone assumed the brown tinge. In th€
tests at the lower temperature both of the cubes developed a
small crack in the coarser seam, but these cracks are so slight
that they would not probably affect the stability of the stone.
In the higher temperature tests the cracking was so great as to
injure the stones considerably, the cracks extending almost
around the cubes. Here, too, the cracks seem to be confined to
the coarser seams so frequent in the stone. The flame tests
broke the pieces from the comers and developed some cracks, one
very bad one in the cube which was subjected to the flame and
water.
No. 222. 550* slow-cooling test.
No. 224. 850** slow-cooling test.
No. 226. Flame test.
No. 223. 550"* fast-cooling test.
No. 225. 850° fast-cooling test.
No. 227. Flame and water test
(40)
Geological Survey, 1906.
Gneiss. Dover, Morris County.
PlvATE VI.
Gneiss from the North Jersey Stone Company's Quarry,
Mt. Arungton, Morris County.
This building stone has a gray color and is uneven in texture.
The finer-grained parts seem to be made up of quartz, feldspar
and black hornblende. The coarser seams give to the stone a de-
cided gneissic structure. ,
Fire Tests. This is another- of the stones which took on a
brownish tinge in the tests. The stones tested at 550° C. devel-
oped some slight, but not serious, cracks. At 850° C. on slow
cooling, several irregular cracks were caused, and on rapid
cooling the stone was seriously cracked, but here, again, the
cracks seem to be confined to the coarser seams. Under the
flarne several pieces were broken from the corner and under the
combined action of the flame and the water the cube was very
materially injured.
No. 228. 550° slow-cooling test.
No. 230. 850° slow-cooling test.
No. 232. Flame test.
No. 229. 550° fast-cooling test.
No. 231. 850° fast-cooling test.
No. 233. Flame and water test.
(42)
Geological Survey, 1906.
Gneiss. Mount Arlington, Morris County.
PUiTt VII.
Gneiss from North Jersey Stone Company's Quarry, Wat-
ERI.OO, Morris County.
The stone, which was tested, has a pinkish color, an uneven
texture and a decided gtieissic structure. The minerals, which
can be seen in the hand specimen, are pink feldspar, light quartz
and green hornblende.
Fire Tests. At 550° C. slow cooling this sample remained un-
affected and on fast cooling developed but one small crack. The
slowly cooled cube, at 850° C, has numerous small irregular
cracks, and the fast-cooled one severial open cracks. The flame
experiments greatly injured the cubes. Not only did they cause
pieces to be broken from the exposed corners, but also caused
some bad cracks in both samples.
No. 234. 550° slow-cooling test.
No. 236. 850° slow-cooling test.
No. 238. Flame test.
No. 235. 550° fast-cooling test.
No. 237. 850° fast-cooling test.
No. 239. Flame and water test.
(44)
Geological Survey. igo6.
Gneiss, WateHoo, Sussex County.
PI.ATE VIII.
Gneiss f^rom Hibernia, Morris County.
This is a gray gneiss of irregular texture, though prevailingly
medium in grain, showing light feldspar, smoky quartz and a
black hornblende or pyroxene. The quarry has not been worked
for a considerable time.
Fire Tests. The cube tested at 550° C. and cooled slowly re-
mained unaffected. The sample heated to 850° C, and cooled
rapidly, developed a brown tinge and was quite badly cracked.
It looked as if a blow would easily crumble it. The cube, sub-
jected to the flame and water test, was not only badly cracked but
also lost several pieces from the comer.
No. 240. 550** slow-cooling test.
No. 241. 850° fast-cooling test.
No. 242. Flame and water test.
(46)
Geological Survey, 1906. PLATE VIII.
Hibernia, Morris County.
»
i
Pirate IX.
Gneiss ]?rom P. Lubey's Quarry, Morristown, Morris
County.
The stone from this locality is very variable, both in texture
and composition. The cubes, which were tested, have a gneissic
structure, a greenish color and are comparatively even in tex-
ture. The entire mass has the appearance of a serpentinized rock.
Fire Tests. The stone assumed a brownish tinge. Several
small cracks developed on the polished surface after the cube had
been heated to 550° C. and slowly cooled. The fast-cooled
sample, at this same temperature, developed one bad crack around
three sides. It is interesting to note that in this sample the cracks
seem to have no definite relation to the direction of the gneissic
banding, which is quite different from the usual relation. At
850° C. both cubes were considerably damaged, so much so as to
cause them to crumble. While the flame and water test did not
disintegrate the cube so much as did the flame test, it developed
considerably more cracks, so many as to cause the cube to
crumble if struck a slight blow.
No. 243. 550° slow-cooling test. No. 244. 550° fast-cooling test.
No. 245. 850° slow-cooling test. No. 246. 850° fast-cooling test.
No. 247. Flame test. No. 248. Flame and water test.
Note the large crack in 246 and the corner of 247.
(48)
Geological Survey, 1906.
Gneiss, Morristo\
4 GEOI.
Plate X.
Diabase from P. W. Wilson & Co/s Quarry, Plainfield,
Somerset County.
This is a very fine-grained rock of a greenish color, quj
dense and hard, containing a number of spherules of calcite, soi
of which are an eighth of an inch in diameter.
Fire Tests. No cube was tested at 550° C. slow cooling,
the fast-cooling experiment the stone assumed a brownish tii
and showed one irregular crack around three sides, besides soj
other smaller ones. In the 850° C. tests the samples were brol
into a number of small pieces, due to pressure exerted by the
caping carbon dioxide formed in the calcination of the calcj
If the calcite were not present it is quite probable that the st(
would have acted well. The flame caused some small craj
and a number of spalls, while the flame and water broke a lal
piece from the corner, a few spalls from the sides and develoj
several small cracks.
No. 200. 550° fast-cooling test.
No. 201. 850** slow-cooling test. No. 202. 850° fast-cooling test.
No. 203. Flame test. No. 204. Flame and water test.
(50)
Geological Survey, 1906.
Diabase. Plainfield, Somerset County,
Plate XI.
Diabase, B. M. & J. S. Shanley's Quarry, Lambertvii.le,
Hunterdon County.
This stone has a greyish-black color and a medium texture.
In the hand specimen much pyroxene and some feldspar can be
recognized.
Fire Tests. In the 550° C. tests the cubes were slightly cracked,
the fast-cooled samples slightly more so than the slowly cooled
one, but, in both cases, not enough materially to weaken the
stone. At 850^ C. the cracking was more pronounced, but only in
the rapidly cooled sample enough to damage it; here an open
crack extends around three sides of the cube.* Small pieces were
lost and several small cracks were developed in the flame tests.
No. 255. 550** slow-cooling test.
No. 257. 850° slow-cooling test.
No. 259. Flame test.
No. 256. 550° fast-cooling test.
No. 258. 850** fast-cooling test.
No. 260. Flame and water test.
(52)
Geological Survey, 1906.
Diabase. Lambertville, Hunterdon County.
PI.ATE XII.
Sandstone, De Graves Bros. Quarry, Wilburtha, Mercer
County.
This stone is very variable, both in color and texture. The
good stone is brown, fine-grained, quite compact and hard.
Much of it is a poor grade, being soft and porous and of an un-
even texture, even being coarse enough to be termed a conglom-
erate in which quartz and weathered feldspar are easily dis-
tinguishable. It is used for structural purposes. The stone, in
the thin section, was seen to be composed of angular grains of
quartz and much weathered feldspar, cemented rather loosely by
limonite, thus leaving many pore spaces. Some plagioclase,
biotite scales and ore grains, probably magnetite and pyrite, were
also noted. The texture of the section examined is rather fine,
the grains averaging one-fifteenth of a millimeter in diameter.
Fire Tests. At 550° C. slow cooling the sample showed one
crack around three sides, parallel to the bedding, and the rapidly
cooled cube showed several, but not serious cracks. The tast-
cooled cube, which was the only one tested at 850° C, was badly
damaged. It split into two pieces along the bed, and one of these
pieces in turn split into two across the bed. Besides this, sev-
eral smaller cracks and some spalls were caused. In the flame
tests both of the samples were broken in two along the bedding,
and other smaller pieces were lost, the cube subjected to the
flame and water being damaged to the greater extent.
No. 64. 550° slow-cooling test. No. 65. 550° fast-cooling test.
No. 66. 850** fast-cooling test.
No. 172. Flame test. No. 140. Flame and water test.
(54)
Geological Survey, 1906.
Sandstone. Wilburtha, Mercer County.
'T*..
PI.ATE XIII.
Sandstone, S. B. Twinning Co., Stockton, Hunterdon
County.
This is a hard compact stone of a light-gray to bluish color,
used as a building stone. The blue variety is rather finer in tex-
ture than the lighter stone, which is coarse enough in places to
show quartz and weathered feldspar. The entire rock is spotted
with limonite stains. The microscope showed angular grains of
crushed quartz and weathered feldspar held together rather
firmly by silica, some calcite and limonite. Among the feldspars
microcline, plagioclase and microperthite were distinguishable.
Patches of limonite were numerous. The grains vary somewhat
in size, the. largest being over a millimeter in diameter and the
• average about three-fifths of a millimeter.
Fire Tests. Both of the cubes in the 550° C. tests showed but
few slight cracks. But at 850° C. the samples were quite badly
cracked. Here, as is different from the behavior in most sand-
stones, the cracks are irregular. This is due to the coarseness
of grain and the absence of distinct bedding planes. The samples
assumed a slight brown tinge. The cube, which was subjected
to the flame and water test, broke into a number of pieces.
No. 47. 550** slow-cooling test. No. 49. 550** fast-cooling test.
No. 46. 850® slow-cooling test. No. 48. 850** fast-cooling test.
No. 141. Flame and water test.
(56)
Geological Survey, 1906.
Sandstone. Stockton, Hunterdon County,
.*
PI.ATE XIV.
Sandstone, Stockton Stone Co/s Quarry, Raven Rock,
Hunterdon County.
This sandstone, which is used for building purposes, is light
gray in color, has an even texture of a fine grain and is quite
compact. The microscope showed that the stone is composed of
rather angular to rounded grains of quartz and weathered feld-
spar cemented by limonite and calcite in a compact manner.
Plagioclase, orthoclase, and microcline could be distinguished and
a few grains, probably of magnetite and pyrite are scattered
through the section. The grains average three-tenths of a milli-
meter in diameter.
Fire Tests. The rapidly cooled sample at 550° C. developed a
few more cracks than the slowly cooled one, hut, in both cases
the injury was slight. At 850° C, however, the cubes were badly
injured. The slowly cooled stone showed up some irregular
cracks, besides being broken into two. While the fast-cooled
cube was not broken into two pieces it was considerably cracked.
In both of the flame tests the exposed corners were broken.
No. 50. 550° slow-cooling test. No. 51. 550° fast-cooling test.
No. 52. 850° slow-cooling test. No. 53. 850° fast-cooling test.
No. 173. Flame test. No. 142. Flame and water test.
(58)
Geological Survey, 1906. PLATE XIV.
Sandstone. Raven Rock, Hunterdon County.
PI.ATE XV.
Sandstone, W. E. Barti^e's Quarry, Martinsvii<i.e, Somer-
set County.
*
This stone, which is widely used for building purposes, is light
gray in color, quite fine-grained and even in texture and fairly
compact. The microscope showed that the grains are angular to
rounded, average three-twentieths of a millimeter in size and are
mostly quartz, though there is much weathered feldspar and some
mica present. The cement is largely calcite, with some limonite.
A few grains of mag^itite were noted in the section.
Fire Tests. The rapidly cooled cube at 550° C. remained unin-
jured, while the slowly cooled sample developed a small crack.
This stone also took on a brownish tinge. At 850^ C, upon fast
cooling, the stone showed one bad crack around three sides.
Under the flame several small pieces were broken from the front
edge, and under the flame and water test a much larger portion
was lost.
No. 'J2, 550° slow-cooling test. No. 73. 550** fast-cooling test.
No. 74. 850** fast-cooling test.
No. 175. Flame test. No. 144. Flame and water test.
(60)
Geological Survey, 1906,
Sandstone, Martinsville, Somerset County.
PI.ATE XVI.
Sandstone^ F. W. Shrump's Quarry^, Pi,easantdai,k, Essex
County.
This building stone, brown in color, is quite variable. The
good stone is fairly even grained and fine in texture, but it grades
into a loose, coarse-grained stone, which, in places, splits very
easily along the bed because of the presence of numerous scales
of mica. Under the microscope the grains appeared to be sub-
angular and are held together by a limonite cement. The stone
is not very compact. The grains, which average one-tenth of a
millimeter in diameter, are largely quartz and weathered feldspar,
with some weathered mica scales and a few apatites.
Fire Tests. Little damage was done in the 550° C. tests; the
sample which was cooled slowly remaining unchanged and only
one insignificant crack developing in the fast-cooled sample. At
850° C. the cubes suflFered great injury; the slowly cooled stone
split into two pieces and was otherwise badly cracked and the
rapidly cooled sample was so injured as to make it worthless.
Under the flame the stone resisted well, being cracked only
slightly at the front edge, but under the combined action of the
flame and water the sample was badly broken.
No. yT. 550° slow-cooling test. No. 78. 550° fast-cooling test.
No, 76. 850° slow-cooling test. No. 75. 850° fast-cooling test.
No. 179. Flame test. No. 148. Flame and water test.
(62)
Geological Survey, igo6.
Sandstone. Pleasantdale, Essex County.
PI.ATE XVII.
Sandstone, Bei.i.Evii,i,e Stone and Quarry Company, Avon-
DAI.E, Essex County.
The stone from this extensive quarry is a brown stone of a
rather medium texture, firm and compact. The texture, as shown
in the thin section, varies somewhat, the average size of the angu-
lar and subangular grains being one-third of a millimeter, though
there is much of a coarser and finer texture. Quartz and cloudy
feldspar, with some plagioclase, make up most of the stone,
though many colorless scales of mica are scattered through the
mass. The cementing material is limonite and calcite in about
equal proportions and the stone appears quite compact and firm.
Fire Tests. The cube tested at 550° C. and cooled without the
action of water remained unaffected. The' fast-cooled sample
at 850° C. was split into two pieces along the bed and was also
slightly darkened in color. The sample put through the flame
split in two, showed several cracks and lost several pieces from
the exposed edge.
No. 108. 550° slow-cooling test. No. 180. Flame test.
No. III. 850° fast-cooling test.
Another sample, from the same .locality, is grayish brown in
color and of a coarser and more uneven texture, the latter, as
shown by the microscope, varying considerably. Some grains
exceed a millimeter in size, while there is much that is finer.
Quartz and feldspar with some microcline and microperthite are
the sole constituents, with the exception of a few scales of color-
less mica. The cementing material, as in the other sample from
this locality, is limonite and calcite, though there is less of the
latter in this stone than in .the brownstone. This sample is more
compact than the brownstone.
Fire Tests. The cube tested at the lower temperature remained
uninjured, but assumed a brownish tinge. At 850° C. on slow
cooling there were developed two slight cracks of marked irregu*-
larity, differing in this respect from those in the finer-grained
stone from this same locality. It would seem, then, that the
coarseness of grain caused an irregularity in the cracking. The
flame and water caused the cube to be so broken as to make it
worthless.
No. 109. 550** fast-cooling test. No. 149. Flame and water test.
No. no. 850** slow-cooling test.
(64)
Geological Survey. 1906. PLATE XVII.
Sandstone. Avondale, Essex County.
5 GEOI.
PI.ATE XVIII.
Sandstone, Geo. Bayuss^ Quarry, North Arungton, Hud-
son County.
This stone, where fresh, is light gray in color, but, for the
most part, it is stained with iron and copper compounds. Where
fresh it is hard, compact and fine grained, but because of the
amount of weathering it has undergone, it is rather loose and
porous. It is locally used as a building stone. In thin section
the texture was seen to vary somewhat. Most of the mass is fine
grained, though some of the grains reach the size of a millimeter.
The stone is made up of fairly rounded fragments of somewhat
cracked quartz and cloudy feldspar, the latter mineral being the
more abundant. As a whole the mass is loosely cemented by
limonite, but in places there seemed also to be a cementing ma-
terial made up of finely crystalline quartz and feldspar.
Fire Tests. But three samples of this stone were tested. The
550° C. slowly cooled cube remained uninjured, but assumed a
slight brown tinge. The fast-cooled cube at this same tempera-
ture developed one small crack across one corner. The sample
after being subjected to the flame and water test went to pieces.
No. 80. 550° slow-cooling test. No. 79. 550° fast-cooling test.
No. 150. Flame and water test.
(66)
Geological Survey, 1906. PLATE XVIII.
Sandstone, North Arlington, Hudson County.
Plate XIX.
Sandstone, J. GamblEE and Son, Closter, Bergen County.
This stone is coarse grained and light gray, showing, in the
hand specimen, weathered feldspar and quartz. It varies some-
what in texture, yet is all quite coarse. The microscope showed
that the mass is rather firmly cemented together and the grains
are well interlocked. The cementing material is largely limonite,
but the secondary enlargement of both the quartz and feldspar
has made the stone firm and compact. The grains are irregular,
angular and quite variable in size, the largest being over a milli-
meter in diameter. Quartz, showing evidences of crushing, and
feldspar make up the body of the stone in about equal proportions.
The feldspar, which is somewhat weathered, is mainly an acid
plagioclase and microline, with some microperthite and microcline
microperthite. A few zircons and apatites were also noted in the
section.
Fire Tests. Both of the cubes tested at 550° C. remained unin-
jured. The 850° C. slow-cooling test caused the stone to lose
most of its durability, for it was split into a number of pieces by
irregular cracks. In the flame test a small piece was broken from
the exposed corner. Under the action of the flame and water the
sample seems to have remained uninjured.
No. 70. 550° slow-cooling test. No. 71. 550** fast-cooling test.
No. 69. 850° fast-cooling test.
No. 181. Flame test. No. 151. Flame and water test.
(68)
Geologica) Survey, 1906.
Sandstone. Closter, Bergen County.
5* GBOL
PI.ATE XX.
White Limestone^ B. Nicoi.1. & Co., Frankun Furnace^
Sussex County.
This is an exceedingly coarse-grained, well-crystallized white
limestone, some of the crystals of which are over two inches in
size. The color is white to pale bluish. Scattered through the
mass are scales of mica and graphite and other dark minerals.
It is not used as a building stone.
Fire Tests. A sample, after having been heated to 550° C. and
cooled rapidly remained apparently uninjured. The 850^ C. tests
badly damaged the cubes. Both were considerably cracked, cal-
cined and -crumbled. Several cracks were caused and several
small pieces were broken from the edge of the sample in the flame
test and in the flame and water experiment large pieces were lost
and small cracks developed.
No. 211. 550** fast-cooling test.
No. 212. 850** slow-cooling test. No. 213. 850° fast-cooling test.
No. 214. Flame test. No. 215. Flame and water test.
(70)
Geological Survey, 1906.
e (Marble). Franklin Furnace, Sussex County,
PI.ATH XXL
Limestone, O'Donnei. and McManiman's Quarry, Newton,
Sussex County.
This is a fine-grained, crystalline, blue and hard stone in which
veins of white calcite locally occur. It is highly mag^esian.
Fire Tests. Both cubes, in the 550° C. experiments remained
unaffected. In the 850° C. tests the calcination was slight, because
the stone is largely dolomitic. The slowly cooled sample shows
several small and irregular cracks, the fast-cooled sample likewise
shows several small cracks, and it flaked a little because of the
calcination, but in both cases the injury is not great. In the
flame tests the cubes were considerably affected, being broken
into pieces on the exposed corners and edges.
No. 216. 550** slow-cooling test.
No. 218. 850** slow-cooling test.
No. 22a Flame test.
No. 217. 550° fast-cooling test.
No. 219. 850** fast-cooling test.
No. 221. Flame and water test.
(72)
Geological Survey, igo6.
Limestone. "Newton, Sus
V
PI.ATE XXII.
Limestone, Phii^upsburg, Warren County.
This is a fine-grained, hard, crystalline dolomitic stone of a
bluish color, in which are numerous, coarsely crystalline veins of
calcite.
Fire Tests. The 550° C. slowly cooled cube remained un-
affected, but the rapidly cooled sample developed several small
cracks. In both tests at 850° C. irregular cracks were caused
along the calcite veins and there was some flaking due to the
slight calcination. The flame test broke a small piece from the
corner and caused several cracks. The combined action of the
flame and water caused the sample to be broken into a number of
pieces.
No. 249. 550** slow-cooling test.
No. 251. 850° slow-cooling test.
No. 253. Flame test.
Na 250. 550* fast-cooling test.
No. 252. 850** fast-cooling test.
No. 254. Flame and water test.
(74)
Geological Survey. 1906. PLATE XXII.
Limestone. PhiUipsburg, Warren County,
Pl^TE XXIII.
*
ARGII.UTE Rock, Margerum Bros., Princeton, Mercer
County.
The stone from this locality is an extremely fine-grained rock
of a slate color. It looks much like a shale or a slate and splits
readily along the bedding planes. It is used for structural work.
The microscope reveals the presence of many cavities filled
or partially filled with opal. Some little quartz grains are scat-
tered through the mass, which seems to be an extremely fine-
grained calcareous material, mixed with much clay.
Fire Tests. Upon slow cooling, after being heated to 550° C,
the cube was split along the bedding and showed other cracks.
Upon cooling rapidly from the same temperature, some trans-
verse cracks were developed, but the worse cracks were parallel
to the bedding. The flame test developed one slight crack along
the bed and around three sides, while the flame and water to-
gether broke a small piece off the upper edge, besides cracking
the sample around three sides along the bedding.
No. 98. 550** slow-cooling test.
No. 178. Flame test.
Dec. 15, 1907.
No. 99. 550° fast-cooling test.
No. 143. Flame and water test.
{76)
Geological Survey, 1906. PLATE XXIII.
Argillite. Princeton, Mercer County.
PART n.
The Glass-Sand Industry of New Jersey^
By HENRY B. KUMMEL and R. B. GAGE.
6 GEOL (77)
The Glass-Sand Industry of New Jersey*
BY HENRY B. KUMMEL AND R. B. GAGE.
Introduction, — This rqx)rt on the glass sands is part of a
larger investigation of the sand deposits of the State, commenced
nearly two years ago by the Geological Survey. Since numerous
inquiries have been received for information regarding the glass
sands in particular, the following paper has been prepared for
publication at this time.
Condition of the industry. — During the last ten or fifteen
years the glass-sand industry of this State has witnessed a
marked decline in the price received for sand, due to the intro-
duction of labor-saving machinery and competition. There is
also a tendency towards consolidation, which has resulted in the
partial elimination of the small producer. This drop in price
has stopped the mining of glass sand at some pits and caused the
installation of modem plants to handle the sand on a larger scale
at others. Those companies which have ceased to mine this
grade of sand are mixing their glass sand with the top layers of
the sandy loam and clay and selling the mixture for foundry
purposes. This is particularly true when the glass sand is of an
inferior grade, or else very small in amount compared to the
foundry sand mined.
Since there is practically little or no glass sand exported from
the State, any cause that has a tendency to increase or decrease
the prosperity of the glass industry of the State will naturally
have a corresponding effect on the glass-sand industry. A rise
in the price of the manufactured article, or decrease in the cost
of producing the same, will encourage the manufacturer to en-
large his output, which will increase the demand for sand. The
•cost of labor being practically the same throughout the country,
(79)
8o THE STATE GEOLOGIST.
the principal remaining factors that determine the prosperity of a
glass industry in any particular locality are cost of fuel, sand and
freight rates.
The cost of fuel in the New Jersey field is high when com-
pared to the cheap fuel available jn the natural gas fields of
Indiana and Kansas, but experience has shown that the supply
of natural gas is far from inexhaustible, and within recent years
there have been many removals from the waning gas fields of
Indiana to the new gas fields of Kansas. Even when compared
with other fields using coal, the location of the New Jersey
field is not particularly advantageous, although it is not greatly
removed from the coal fields of Eastern Pennsylvania. It has,
however, the tremendous advantage of close proximity to the
markets of the large cities of the East.
While the individual sand deposits of New Jersey are not .
so large as those of the Middle West or Pennsylvania, they
can be operated much cheaper and with a much smaller initial
investment. The latter deposits are mostly sandstone, that
must be blasted out and crushed before washing. Often these
deposits are capped by shale or limestone of so great thickness
as to compel mining by tunneling, instead of in an open pit.
The New Jersey deposits are always capped by more or less
sandy gravel, but this capping is not always a detriment in dig-
ging, for it is sometimes profitably sold for foundry purposes.
Again the New Jersey producer gets 90 ceiits per ton for his pro-
duct, compared with 60 to 65 cents per ton in Illinois and Mis-
souri.^
Area of the Held. — Throughout the -greater part of the south-
ern half of the State, the surface gravel is underlaid by beds of
sand. In some places these beds have been found to be 90 feet
thick. Along the river banks they can be plainly seen where
undercutting of the bluff has exposed them. These beds are
often pure enough to be of value for glass, and are dug for this
purpose. The principal localities in which they are being dug
to-day are (i), along the Maurice River below Millville; (2),
the region around Vineland, and ( 3 ) , that around Williamstown,
*U. S. Geological Survey, Bulletin No. 285, p. 461.
GLASS SAND INDUSTRY. 8i
although twenty-five years ago glass sand was being mined as far
east as Egg Harbor and west to Salem. The drop in the price of
sand was probably the controlling factor that caused the con-
traction in the area of the productive field. Since glass sand is
widespread geographically, and the supply is always greatly in
excess of the demand, only those pits which can be worked most
cheaply have continued in operation.
On account of the bulky nature of the sand, the cost of trans-
portation is one of the leading items that determines the value of
a pit, and consequently its life. This naturally confines the pro-
ductive area of a glass-sand field to the vicinity of a railroad or
navigable river. Practically every producing pit in southern
New Jersey is less than one mile from a- railroad or is along a
navigable stream, although there is no doubt but that good un-
developed deposits of glass sand exist elsewhere in this region.
Since cheap transportation is so vital a factor, there is small
chance for the immediate development of the more distant areas.
Even the territory that is within a mile of the railroads has not
been thoroughly developed, or even tested.
The prodiicing fields. — The present producing field is natur-
ally divided into three districts, the Maurice River, the South
Vineland and the Williamstown.^
The Maurice River district is just south of Millville, along the
Maurice River, where the beds of sand can be seen for several
miles along the river banks. The sand from this district is all
shipped in barges, which fact naturally confines the pits to the
banks of the river or a short distance inland.
The West Jersey railroad traverses the South Vineland dis-
trict, the village of South Vineland being about its center. All
the pits are within J/2 to ^ of a mile of the railroad, and are
scattered at irregular intervals for about 3 miles along it.
This district would no doubt be much enlarged if the demand
increased or the price rose sufficiently to justify operations at a
greater distance from the railroad than at present.
The Williamstown district covers a much larger area than
either of the other two. The pits are scattered along the Wil-
^Some glass sand is dug also at isolated points not included in these dis-
tricts, as at Jamesburg, Middlesex county.
82 THE STATE GEOLOGIST.
liamstown and Delaware railroad from Downer nearly to Atco,
a distance of lo miles. In most cases they are widely separ-
ated, leaving plenty of undeveloped territory adjacent to the '
railroad. . Some new deposits have recently been discovered
in this field, and are being developed. Judging from the size of
the field, much good glass sand within this area is probably as yet
undiscovered. If such is the case, this district alone could supply
the demands of the glass industry for years to come.
Description of the deposits, — ^All the glass-sand deposits of
southern New Jersey are capped by layers of gravel, sand and
loam, varying in thickness from i to 15 feet or more. Below
Millville, along the Maurice River, the low hills are capped by
gravel deposits, the thickness of this covering depending on the
height of the hill, as little gravel is found in places below the top
of the sand horizon proper, except as small pockets in the sand
beds. These gravel deposits are, in many instances, of value for
foundry purposes, road metal and other uses. The glass sands of
this locality that are of commercial value all lie from 30 feet above
sea level to a shallow depth below. The deposits are mostly on
the west bank of the river, where the erosion of the river and its
tributaries has exposed them.
There is no doubt but that the sand beds extend an indefinite
distance back from the river under the gravel capping, and at one
point a small pit is now being worked about a mile back from
the river. While there is no reason to suppose that the sand
beds pinch out away from the river, nevertheless, the character
of the sand may change from place to place so as to ruin it for
glass purposes. The increased expense of opening up and work-
ing a pit any distance from the river has discouraged operators
from trying to discover new deposits in that direction.
Several different grades of sand, sometimes as many as five,
frequently occur in a single bank. These different layers vary-
not alone in the iron and clay content, but also in the size and
character of the sand grains. The various layers are frequently-
separated by thin sheets of clay. Sometimes one grade changes
abruptly into another, while elsewhere there may be a gradual
transition from a fine to a coarse grain, or vice versa. Changes
in the size of the grains are frequently accompanied by varia-
GLASS SAND INDUSTRY. 83
tions in the clay and iron content. Not uncommonly, the sand
immediately below the gravel beds is fine grained, rich in clay
and contains too much iron for glass use, but it is often mined
and sold for foundry purposes. As the grains increase in size,
the beds often become whiter with the lowering of the iron and
clay content, until the best grade of glass sand is reached near
the water level. Although the largest grains do not always
occur at or below the water level, the beds of these grains are
mostly lower in clay and other impurities than when composed of
small grains.
The topography of the South Vineland district is not so broken
as that near Millville. The land is slightly rolling and mostly
under cultivation. The overlying gravel, averaging only from
3 to 5 feet, does not form- so thick a covering as in the Maurice
River district. Immediately below the surface layer, the sand is
sometimes finer grained than the glass-sand grade, but often dif-
fers only in the amount of the clay and iron content. In the
latter case, the sand gradually gets purer with depth until suit-
able for glass. The ground waters apparently contain very little
iron, as often the best grade of sand is found below the water
level. Some of these pits have been worked over large areas,
but seldom deeper than the water level. In mining, the stripping
has been thrown on the mined ground, and no doubt has often
covered first-class sand. From, the cursory examination made,
it was impossible to tell whether the deposits pinched out at the
edges or gradually became valueless for glass by becoming im-
pregnated with iron.
• Throughout the white sand there are frequently iron-stained
streaks or seams, which are generally quite narrow and cause
little or no trouble. Sometimes, however, they are 6 to 10
inches thick, and then must be separated from the purer sand
before washing. The sand above, between and below them may
be first-class glass sand.
Pockets of blue clay, sometimes of considerable size, occur not
infrequently in the sand beds, but being sharply separated from
them cause comparatively little trouble in mining. Sometimes
layers of clay 2 to 3 feet thick are found just below the gravel
covering resting on top of the glass-sand beds.
84 THE STATE GEOLOGIST.
The Williamstown district resembles the South Vineland dis-
trict very much in topography, character and depth of the gravel
covering. The fine, loamy foundry sand sometimes is wanting
between the gravel layer and the white glass sand beneath. Often
in different parts of the same bank, the foundry sand occurs at
the level elsewhere occupied by the glass sand. In some of these
pits, the best sand is found below the water level, while in other
instances the percolating iron-bearing waters have ruined the de-
posit below this point. In certain spots these chalybeate waters
have coated the grains of the entire glass sand beds, rendering the
deposit valueless at this point. Lenses of a clean, sharp small-
pebbled gravel, which are of a different character than the gravel
covering, are found in some of these sand beds.
Mining methods, — ^There are two general methods of mining
in use throughout the glass-sand field. By the older method, after
stripping, the sand is shoveled into carts or cars and hauled to the
washer. By the newer method, the sand, suspended in water, is
pumped from the bottom of the pit and forced through a 4 to
6-inch pipe to the washer.
The former method has the advantage of producing a higher
grade of sand than the latter method, where there is much varia-
tion in the character of the beds, as the impure sand can be sepa-
rated to a certain degree and discarded before washing, so that
deposits can be mined by this method that would be worth-
less if mined by the latter. The depth to which deposits can be
dug by the old method is mostly determined by the height to which
the ground water rises in the pit, as little sand is mined below the
water level. In some pits this objection is of little importance,*
as the sands are valueless below this point, while in other in-
stances the best grade of glass sand is found below this level.
The cost of handling sand by this method, however, is so much
greater than by the pumping method that its advanta;ges are
clearly outweighed by this one drawback, and therefore it is being
rapidly replaced by the modern method at all pits where condi-
tions are not absolutely prohibitory.
A deposit to be mined by the pumping method must be. fairly
uniform and free from iron-stained seams of any considerable
thickness. One containing seams could not be mined at all by
GLASS SAND INDUSTRY. 85
this method, for washing- would not remove these iron-stained
grains, and , they could not be removed otherwise, unless the
seams are all found above the water level. In this case, they can
be dug out separately before the sand falls into the water. The
bottom of the deposit must also be a few feet below the level of
the ground water, of which there must be a sufficient supply to
keep the pit well filled in addition to furnishing what is needed
for washing. In Plate XXIV this method of mining is fairly
well shown. The white bank on the right is the glass sand, from
which the overburden has been stripped off for a few yards back.
' On the left is the waste pile of stripping which has been wheeled
or carted across the bridge shown in the cut and dumped on the
mined ground. Between these two banks a small, flat-bottomed
boat, containing a suction pump and such other machinery as is
necessary for pumping the sand and water, is seen in operation.
The intake-pipe is kept a few feet under water and within a short
distance of the sand bank. When this pipe is kept at the proper
distance from the bank, the water pumped will contain from 20 to
30 per cent, sand, the amount of sand carried and the size of the
g-rains increasing with the velocity of the water. The mixture of
sand and water is forced directly to the washer through the pipe
seen leading off to the left.
Any clay adhering to the sand grains is softened and de-
tached from the grains during mining and washing, owing to the
preliminary soaking to which it is subjected. With a medium-
sized, well-equipped plant, 10 men can easily mine and wash 250
tons of sand per day of 10 hours.
The digging of glass sand requires quite an initial investment
to open up a deposit and install a modern plant. Strong compe-
tition between the different producers has lowered the price, so
that, as already mentioned, at not a few pits which formerly pro-
duced some glass sand, none is now mined. Those companies
which do not adopt the newer methods will probably soon find it
unprofitable to mine at the lower price, and must either install an
up-to-date plant or else cease producing this grade of sand.
Method of washing. — The method of washing glass sand in
use throughout the New Jersey glass field is a comparatively
86 THE STATE GEOLOGIST.
simple process. The sand is washed into the upper end of an in-
clined revolving cylindrical screen, about 4 feet long and 18 inches
in diameter, and gradually works towards the lower end as the
cylinder revolves. This screen allows all grains smaller than
^/4oth of an inch (30 mesh) in diameter, to pass through into a
trough below. Grains larger than this size pass out of the lower
end of the cylinder and are rejected. The clay and loam, pass
through the sieve together with the glass sand, so that this pre-
liminary treatment eliminates only the material too coarse for the
glass manufacturer.
After passing through the screen, the sand is caried up a series
of inclined flumes by endless chains and scrubbers (Plate XXV).
As the sand passes slowly up these flumes the water runs back,
carrying whatever clay and fine sand remains suspended in it.
Impurities too heavy to remain suspended pass on with the sand,
which is at last dumped in a pile outside the washer, where the
excess of water is allowed to drain off before loading into cars.
The scrubbers move so slowly up the nearly level flumes that only
the fine clay and loam is removed. It is not uncommon to find
in the washed sand ^ to i per cent, of the grains so fine that
they will pass a 200-mesh sieve, and often 4 per cent, are finer
than the 120-mesh sieve. If the scrubbers were made to travel
faster or the flumes given a more inclined position, much more
of this fine material would be removed, a result to be desired.
PHYSICAL PROPERTIES.
The physical character of a glass sand is of importance, al-
though not so much so as the chemical composition.
Shape, — It is the prevailing opinion throughout the glass-sand
field that the sand grains should be sharp and angular, never
rounded and smooth. This opinion does not" appear to be al-
together well founded, as the ordinary grades of glass, as well
as the fine flint wares, are being successfully made in the Missis-
sippi Valley field from sands composed entirely of the latter type.^
*U. S. Geological Survey, Bulletin No. 285.
GLASS SAND INDUSTRY. 87
The New Jersey sands are prevailingly subangular. Most of
the grains show irregular fracture surfaces, angles and edges,
which in the case of those larger than ^/^^ of an inch (40-mesh)
are more or less rounded, while of the grains smaller than ^/loo
of an inch there are almost none which are not sharply angular.
The grains of intermediate size are slightly worn, but not enough
to change greatly their original shape. On the whole the sands
would be classed as sharp and angular rather than round and
smooth. The samples examined from the South Vineland district
are somewhat more worn than those from the Williamstown.
Plates XXVI and XXVII are photomicrographs of the sands,
magnified 10:5 diameters, which show better than words their
shape.
Size, — ^The grains should not be too small or too large, and
as uniform in size as possible. If the majority of the grains have
a less diameter than 0.136 mm. (passing a sieve having 120
meshes per linear inch), the sand is said to "bum out" in the
batch and will not produce as much glass per unit as when
composed of coarser grains. The fine grains also have a ten-
dency to settle to the bottom of the batch, thus preventing the
forming of a homogeneous mixture. When the grains are uni-
formly larger than 0.64 mm. (30 mesh) in diameter, more time
is required to fuse them than otherwise. This lowers the amount
of sand each furnace can melt per day and increases the cost of
the glass produced.
The determination of the sizes of the grains can be best made
by passing a known amount of sand through a series of sieves^
arranged in regular order, that with the coarsest mesh being at
the top. A convenient quantity of the sand having been placed
in the top sieve, the whole series, held firmly together is
given a certain number of shakes, either by hand or in a machine,
more rapid and satisfactory results being secured with a machine.
After shaking, the amount found in the pan under the bottom
sieve is weighed and the weight recorded. Then the amount
found on the bottom sieve is added to that in the pan and the
* A very convenient series of sieves reading from the bottom up according
to mesh are 200, 140, 120, 100, 80, 60, 40, 30, 24, 18, 10, J4» Vi« and 1/2.
88
THE STATE GEOLOGIST.
whole weighed and recorded. This is continued until that found
on all the sieves has been weighed, and the amount that has
passed each sieve determined. If a weight of loo grams were
originally taken, the percentage which has passed each sieve can
be read directly from these weights without further calculation.
Samples of washed glass sand from many of the deposits in
the State have been examined by the above method, with the
results shown in the following table:
Table showing the per cent, of grains passing the different sieves.
MESH OP
SIEVE.
661B
664A 665C
666A
669A
670B
671A
672A
663
10
99.8
99.7
99.4
98.3
93.7
53.1
26.S
5.2
2.3
0.7
99.7
99.5
98.4
93.7
73-6
22.2
II. I
2.5
1.4
0.4
99.8
99.2
98.5
95.8
85.4
25.4
11.5
1.4
0.5
0.0
99.8
99.7
00.'?
l8,
24,
* '99.8'
97.8
18.8
6.2
17
I.I
0.5
99.5
9a6
81.9
1 1.4
37
0.5
0.2
0.1
99.8
99.1
96.3
40.4
22.6
4.4
2.2
0.8
30,
40,
6o,
8o
120,
140,
200,
99.7
98.8
19.5
7-7
1.6
I.I
0.5
99.8
99.2
47.8
16.2
2.6
1.5
07
96.4
61.4
7.4
1.8
0.2
0.0
0.0
From the above table it is apparent that in none of the samples
is there much material which will pass a 120-mesh sieve (open-
ings ^/i87 inch) and very little (except in No. 666A and 663)
which is coarser than a 40-mesh sieve (openings ^/^g inch). In
many of the samples about 60 per cent, of the grains are between
V55 and V90 inches in diameter (40 and 60-mesh). Sample 663
of the table is a Pennsylvania sand cleaned by an air-blast process
rather than by washing. It has 35 per cent, of the grains between
V40 and ^/gg inches in diameter and 54 per cent, between
^/gg and V90 inches, with an entire absence of grains smaller than
^Aio inches (140 mesh) and practically none as small as ^/isi
inches (120 mesh). These statements and the above table indi-
cate the comparative uniformity in the size of grain of a good
glass sand.
Examination of a number of unwashed sands disclosed a
slightly larger percentage, as compared to the washed sands, of
Geological Survey, igo6. PLATE XXVI.
Pig- I-
Well-rounded sand grains from an Ordovician Dolomite, Cushman, Ark.
(van Ingen) — magnified 15 diam.
Fig. z.
Sand grains retained on a 40-mesh sieve, x loj^ diam. Reading Sand
Company, Penbryn.
Geological Survey, 1906. PLATE XXVII.
Fig. I.
Sand from WeJrick and Fields. Radix, x loH diam. Note a f«w
rounded grains.
fii. I.
Sand from Crystal Sand Company, South Vineland, x io% diam.
GLASS SAND INDUSTRY. 89
the sizes rejected in the process of washing already described,
but these differences are not striking.
Impurities. — ^Under the microscope the quartz grains appear
as clear, transparent crystals. Grains of milky or colored quartz
are very rare, and there is little evidence of any impurities such
as clay or iron oxide attached to the grains of either the washed
or unwashed sands. Small grains of other minerals than quartz
are quite numerous in the Williamstown deposits, but much less
so in the samples from the other two fields. These foreign grains
are fairly uniform in size, well-rounded and mostly less than 0.21
mm. (^/i2i inch) in diameter, and will pass an 80-mesh sieve.
They were found to be chiefly leucoxene, rutile, ilmenite and
sphene.^ Since the quartz grains are almost chemically pure
themselves and have practically no impurities attached to them,
these minerals must contain the greater part of the iron, titanium,
etc., which chemical analysis shows are present in the sands. It
follows that if they can be eliminated the quality of the sand will
be much improved.
Chemical composition. — ^An absolutely pure quartz sand would
be 100 per cent, silica (Si02), but an accurate chemical analysis
of even the best glass sands always shows small amounts of the
following substances : iron, alumina, titanium oxide, lime, mag-
nesia and organic matter. These are due to other mineral grains
than quartz usually present in the sand, such as mica, magnetite,
feldspar more or less altered to kaolin, ilmenite, sphene, rutile,
etc., or to films of iron oxide or clay coating the quartz grains.
Some of these cause little or no trouble in a glass sand when pres-
ent in small amounts, while others are very injurious when pres-
ent even in amounts not to exceed ^/loo o^ ^ P^ ^^^^' Chief
among these detrimental substances are the oxides of iron which,
if not already in the ferrous state, are reduced to it in the furnace,
and give the glass a green color. Such substances, as the car-
bonate of lime which may occur as bits of shell or ground-up
limestone can hardly be classed as impurities, since they are added
to the sand in the manufacture of glass, altjiough when present
in the sand they lower the percentage of silica, as shown by the
* Examined and identified by Prof. J. Volney Lewis, of Rutgers College.
90
THE STATE GEOLOGIST.
analysis. The oxides of sodium and potassium which are shown
in small amounts in some analyses of glass sands are not to be
regarded as impurities, as they also are added in making up the
glass batch. A small percentage of clay causes little trouble pro-
viding the clay contains no iron and very little magnesia, but this
is very seldom the case. The water coming from the scrubbers
is almost always a dirty yellow color which indicates the presence
of clay containing considerable iron, some or all of which is in the
ferric state. The following chemical analyses of New Jersey
washed glass sands and of one Pennsylvania sand (663) have
been made especially for this report by the junior author:
Sample No.
Iron
Titanium
Silica
Oxide
Alumina
Dioxide
I«ime
Mafniesia
SiO,.
Fe.O,.
Al.G,.
Tic..
CaO.
MgO.
Organic
Matter
and
Moisture.
661 B,
662A,
663,
664B,
665C,
666A,
667A,
668A,
669A,
669B,
670A,
671A,
672A,
673A,
98.93 %
99.59
99.72
99.40
99.62
9954
99.35
99.52
99.42
99.48
99-39
99.11
99.176
99-55
0.0222%
0.0071 "
0.0017 "
0.0058 "
0.0047 "
0.0039 "
0.0086"
0.0096"
0.0068"
0.0075 "
0.0086"
0.0108 "
0.0114"
0.0049 "
0.4686%
0.1447 "
0.1203 "
0.2752 "
0.142 "
0.2245 "
0.3392 "
0.1856"
0.276
0.204
0.2345 "
0.355
0.366
0.1443 "
tt
tt
ft
tt
0.269 %
0.0728
0.0147
0.0737
0.0543
0.0476
0.1302
0.0868
0.1 17
0.1215
0.1475
0.2213
0.2344
0.0608
0.010%
O.OIO "
0.007 "
0.008"
0.01 "
0.007 "
0.017 "
0.006"
0.01 "
0.006"
0.005 "
0.009"
O.OII "
0.008"
0.008%
0.007"
0.008"
0.012 "
0.005 "
0.009"
0.005 "
0.007"
0.018 "
0.009
0.007
0.023
0.019
O.OII
((
((
((
((
((
0.29 %
0.172
0.134
0.231
0:162
0.166
0.156
0.19
0.156
0.17
0.21
0.19
0.182
0.22
Samples Nos. 664B, 665 C, 666A and 673 A are fairly good
sands for all ordinary kinds of glass, and are often used for flint
glass, but have to be corrected when thus used. Their chief use,
however, is for window, green and amber glass. Sands like 671A
and 672A are used only for the cheaper grades of glass where
the color makes little difference, as in beer bottles. Sample No.
663 is a Pennsylvania sand which is used extensively by the New
Jersey glass manufacturers for the best grades of flint glass.
In regard to these analysis, it is hardly necessary to point out
that they show the composition of the sample analyzed, not neces-
sarily the true average chemical composition of the whole de-
posit. While care was taken to select a fair sample, yet the
GLASS SAND INDUSTRY. 91
amount of sand exposed at any one time during the life of a pit
is a^ very small proportion of the total, and there is no reason for
believing that the sand may not vary slightly in chemical com-
position from place to place.
The whiteness of these sands, often relied upon as a test of
their purity, is a very poor indication of the iron content. Sample
No. 672A is equally as white in appearance as sample 666A, but
the analysis given above shows the former contains more than
three times as much iron as the latter. If the iron were present
as ferric oxide coating the quartz grains, or as one of the bases
in a clay which was attached to the grains, the color might be a
guide to the iron content, but this is not the case. Under the
microscope the quartz grains are seen to be clear and colorless,
and are not stained by iron oxide. We have pointed out that
the sand contains numerous dark-colored minerals, which were
identified under the microscope as leucoxene (probably), rutile,
ilemenite and sphene, their relative abundance being indicated by
the above order. These are heavier than the quartz, and with
slight shaking readily settle to the bottom of a sample. They are
also of a somewhat uniform size and will pass an 80-mesh sieve.
The amount of iron and titanium foimd by analysis is readily
explained by the presence of these minerals in the sands, and one
cannot question the conclusion that the iron content which is
especially detrimental, is due solely to these minerals, particularly
to the ilmenite. If, therefore, some method can be devised
whereby they can be eliminated without too great expense and
the loss of too large a proportion of the quartz sand, the value
of the remainder will be greatly enhanced. By the present method
of washing in use throughout the glass-sand field, no effort what-
ever is made to remove them. They have apparently been over-
looked, or else little importance has been attached to them.
The presence of these heavier minerals in the sand makes it
difficult to obtain a sample which is a fair average of the whole
bank. There was more or less concentration of them during the
deposition of the beds, so that the composition of the sand varies
•from place to place. During transportation, the jarring of a
loaded car, particularly if the sand be dry, is sufficient to cause
considerable concentration of the heavier minerals toward the
92 THE STATE GEOLOGIST.
bottom. Under these circumstances a sample taken from the
top of a load may fail to represent the correct composition of the
sand. If the sand is wet, this concentration during transportation
does not occur, at least to so great an extent.
The iron imparts a green color to the glass, an effect which the
manufacturer sometimes attempts to neutralize by the addition of
manganese dioxide. Since, however, an excess of manganese
gives a pink color, the importance of an accurate determination
of the iron content is manifest. When the iron content of the
sand is fairly uniform, this is comparatively easy, but when this
is not the case the iron value of the sand must be constantly
checked by chemical analysis. We have been informed by one of
the glass manufacturers that this variation of the iron content
was one of the greatest objections to New Jersey sands for flint
glass. No two carloads were apparently the same, and some-
times the sand in different parts of the same car varied con-
siderably. These facts may be due in part to the concentration of
these heavy minerals in certain parts of the bank during deposi-
tion and in part to the concentration of these minerals in the
bottom of the car during transportation.
Bliniination of the iron, — The fact that the minerals containing
the iron will nearly all pass an So-mesh sieve, at once suggests
the possibility of cleansing the sands by sieving. This was done
in the laboratory with two dry samples, numbers 669A and
672A. Convenient quantities of these two sands were thoroughly
shaken in an 80-mesh sieve, and then the iron, titanium and
alumina in the part remaining on the sieve were determined and
the results compared with the previous analysis, as shown below :
Sample No. 66gA. Sample No. 672 A,
Before After Before After
Constituents. Sieving. Sieving. Sieving. Sieving.
FcaO* 0.0068 0.0022 0.0114 0.0029
TiOa 0.117 0.024 0.234 0.0434
AUOa 0.276 0.085 0.366 0.106
By this sieving process the amount of iron in the sample was
reduced to one-third or less, of titanium to one-fifth, and of
alumina to one-third or less. The lime and magnesia being so
GLASS SAND INDUSTRY. 93
low in the original samples, were not determined in the sieved
portions. These sands, which previous to sieving were only
second-grade sands on account of their iron, were by this means
rendered suitable for the manufacture of the best grades of flint
and plate glass, the iron content being as low as in sample No.
663 which is used for this purpose. The samples thus treated
compare very favorably with the sands used by the Pittsburg
Plate Glass and the American Window Glass Companies, as
shown by the following analysis :
Analysis of sand used by the Pittsburg Plate Glass Co}
Constituents. No. i. No. 2, No. 3. No. 4.
Silica (SiCX), 99.21 98.90 98.95 98.94
Alumina ( AUOs) , 30 .20 .50 .30
Volatile matter, 21 .25 .24 .23
Iron oxide (FeaOs) , 003 .002 .0024 .0036
Lime (CaO), 20 .54 .30 .40
Magnesia (MgO), trace .20 .10 trace
99.923 100.092 100.0924 99.8736
When sands of the above composition are used no correction
for color is attempted in manufacturing plate glass.
Analysis of sand used by American Window Ghass Co
2
Constituents. No. i. No. 2. No. 3. No. 4.
Silica (Si02) , 99-99 99714 99-659 99-579
Alumina (AUOa), 008 .280 .310 .350
slight
Iron oxide (FeaOa), trace .006 .011 .021
Lime & magnesia (CaO & MgO), 002 .020 .020 .050
100.00 100.00 100.00 100.00
It is to be noted further that our sieving removed not only a
large percentage of the objectionable minerals, but it also re-
*U. S. Geological Survey, Bulletin No. 285.
* It is to be noted that no water determination appears in these analyses,
and the silica is taken by difference. Consequently, the silica is just as much
too high as the amount of water carried by the sand. Taken from U. S.
Geological Survey, Bulletin No. 285.
7 GKOI.
94 THE STATE GEOLOGIST.
moved all the fine grains under Somesh size. Reference to the
tables of physical tests on p. 88 shows that in five of the eight
samples the part passing this sieve is ii per cent, or less
of the whole; in three cases it is considerably more. The
elimination of these finer grains would make the sand more de-
sirable from a physical standpoint, and probably add something
to its value. The Pennsylvania sand, No. 633, contains less
than 2 per cent of grains finer than an 80-mesh, and it is also
low in iron. Large amounts of it are imported by New Jersey
glass manufacturers annually at a cost of about $3.00 per ton.
If by sieving, the New Jersey sands can be raised, both chem-
ically and physically, to the grade of this Pennsylvania sand,
and enhanced in value from 90 cents to $3.00 per ton thereby,
the problem is worth careful consideration by glass producers.
We have indicated that on the average from 10 to 15 per cent,
of sand grains, practically all including the iron-bearing minerals,
passed the 80-mesh sieve. This fine-grained sand would there-
fore be valueless for glass purposes, but it might not all be a loss,
since sand grains of this size are always sharp and angular and
so will cut much faster than rounded grains. There might be,
therefore, a market for it as grinding material. But even if
there were not, the New Jersey sand producer could well afford
to sacrifice 20^per cent, of his product if the remaining 80 per
cent, could be cheaply raised to the grade of the high-priced sand
imported from Pennsylvania.
We are aware that it is one thing to sieve thoroughly a small
quantity of dry sand in a laboratory and eliminate the finest
grains and the iron minerals, and quite another thing to treat
wet sand effectively and cheaply on a commercial scale and in
large amounts. We have hopes, however, that the inventive
genius of the sand producers may make some use of this sugges-
tion. We do not need to emphasize the importance to the indus-
try of improving the grade of sand if it can be done cheaply.
It is not claimed that the size of the screen used in these ex-
periments is the one that would always give the most satis-
factory results in actual practice. These impurities vary in size
in different deposits, so that a screen of another mesh might be
needed in some localities to get the best results.
GLASS SAND INDUSTRY. 95
«
If it be found impossible in practice to remove these grains by
washing or sieving, there remains the question of magnetic
separation, which has worked so successfully in late years with
various kinds of ore.
Ilmenite and magnetite are both magnetic, as are many other
iron-bearing minerals, and in a dry sand can very probably be
concentrated by the magnet. Whether the process would be suc-
cessful with the wet sand as it comes from the pits and washeries,
and whether it could be economically carried out, are questions
which we cannot enter upon here.
Production. — ^As a producer, New Jersey is surpassed by
five States in the amount of glass sand produced, and by only
four States in value of the product. While the West Virginia and
Pennsylvania producers get on the average $1.50 and $1.31 at the
mines, respectively, per ton for their product compared with 80 to
90 cents in New Jersey, the former deposits are much more expen-
sive to operate than the latter. The Illinois and Missouri pro-
ducers, however, get only about 60 cents per ton.
During the summer &i 1906, the following firms were digging
glass sands :
Pit
No. Owner. Location of Pit.
661 Crystal Sand Co., Maurice Riv^r below Millville.
662 Crystal Sand Co., Cedarville.
664 R. O. Bidwell, South Vineland.
665 John Burns, South Vineland.
666 Crystal Sand Co., North Pit, South Vineland.
667 Crystal Sand Co., South Pit, 'South Vineland.
668 S. W. Downer, Downer.
669 Weirick & Fields, Radix.
670 Reakirt Glass Sand Mining Co., Sicklerville.
671 A. L. Thomas, Tansborough.
672" Reading Sand Co., Penbryn.
673 Wm. Ranagan, South Vineland.
McCoys, - South Vineland.
Appleby Sand & Clay Co., Old Bridge. • '
Henry Wagner,
Asa Redrew,
A table showing the amount of glass sand mined in 1905 in
the different States and value of the same is given below, based
on statistics published by the United States Geological Survey.
96 THE STATE GEOLOGIST.
Short tons. Value.
Pennsylvania, 361,829 $482,937
Illinois, 234,391 146,605
West Virginia, 155,052 225,734
Missouri, 123467 66,401
Ohio, 74,460 79,999
New Jersey,^ 35,673 30,005
Maryland, 17,899 20,108
California, 9,257 8,112
Massachusetts, 4,600 12,000
Georgia, 4,500 4,050
New York, 3,165 3,115
Summarizing the principle facts regarding the glass-sand de-
posits of New Jersey, which have been discussed more or less in
detail above, they may be said to be chiefly these :
ist. The supply of glass sand is sufficient to meet the demands
of the glass industry for an indefinite period.
2d. There are apparently numerous undeveloped deposits ad-
jacent the present railroad lines.
3d. The chances of finding good deposits in localities remote
from the present railroads are equally as good as in localities ad-
jacent thereto, but without cheap transportation they cannot be
utilized at present prices.
4th. The deposits are of fairly good size and can be developed
at a low initial cost compared with the deposits of Pennsylvania
and the Middle West.
5th. The physical character of the sand equals, if it does not
exceed, that of the western fields.
6th. The sand as mined to-day is well suited for the manufac-
ture of green, amber and window glass.
7th. By the elimination of the iron-bearing minerals, either by
sieving, improved methods of washing or perhaps by magnetic
separation, the New Jersey product can probably be made suitable
for the manufacture of flint and plate glass.
8th. They are well located regarding shipping facilities and
the markets of the large cities of the East.
April 2, 1907.
^ Figures obtained by the State Survey indicate that the above production
for New Jersey is far below the actual product. Twenty glass manufacturers
within the State report using 50,692 tons of New Jersey glass sand for year
ending June 30, 1906. The total actual production in 1906 was probably over
100,000 tons.
.
PART m.
The Origin and Relations of the Newark
Rocks*
The Newark (Triassic) G^pper Ores of
New Jersey,
Properties of Trap Rocks for Road
Construction,
By J. VOLNEY LEWIS.
(97)
The Origin and Relations of the Newark Rocks*
BY J. VOI.NEY I.EWIS.
CONTENTS.
Introduction. ,
Extent of the Newark System.
Characters of the Sedimentary Rocks.
Sources of the Sediments.
Origin of the Sediments.
The Tidal Estuary hypothesis.
The Lake Basin hypothesis.
Objections to the foregoing hypotheses.
Hypothesis of Orographic Valleys.
Objections to the Orographic Valley hypothesis.
A Piedmont Plain hypothesis.
Geologic Relations of the Trap Rocks.
Relations of the Extrusives.
The Watchung flows.
The double crest of Second Mountain.
Sand Brook and New Germantown extrusives.
Relations of the Intrusives.
The Palisades, Rocky Hill, Sourland Mountain, Byram.
Offshoots of the Palisades sill.
Cushetunk and Round mountains.
Origin of the Trap Rocks.
Origin of the First Mountain extrusive.
Origin of the double flow of Second Mountain.
Origin of the Long Hill extrusive.
Origin of the Intrusive Trap masses.
Deformation and Erosion.
The supposed fault along the Hudson River.
Age of the faults.
INTRODUCTION.
Extent of the Newark System,
The Newark (or Triassic) system, of New Jersey (PL
XXVIII) is part of a long, narrow belt extending from southern
(99) . . , .]
lOO
THE STATE GEOLOGIST.
New York southwestward across New Jersey, Pennsylvania,
Maryland, and northern Virginia, as shown on the outline map,
Pig. I, and this is but one of several similar disconnected areas
in the Atlantic coastal region from Nova Scotia to Sbuth Caro-
lina. The belt across New Jersey occupies about one-sixth of the
total area of the State, extending from the Hudson River and
the New York State boundary to the Delaware River. It com-
prises the Piedmont region, which is intermediate in elevation
■•
AREAS
OCCUPIED BY THE
NEWARK SYSTEM
0:S,0BOUM»CAC SCRVEV'
j^mtui.
Fig. J.
and surface features between the low, smooth Coastal Plain to the
southeast and the higher and more mountainous Highlands to
the northwest. Its undulating surface is interrupted by several
conspicuous ridges, notably the Watchung Mountains and the
Palisades in the northeast and Cushetunk, Round and Sourland
mountains and Rocky Hill in the southwest.
The rocks of this system have been fully described in the pre-
vious reports of this Survey, particularly by Kiimmel^ about a
^:APtnu9j[ Reports of the State Geologist for 1896, pp. 25-88; 1897, pp. 23-159.
ORIGIN NEWARK ROCKS. ' loi
decade ago. In connection with recent studies of the petro-
graphy of the trap rocks and the occurrence and origin of the
copper ores, however, some conclusions have been reached which
are at variance with views heretofore published, and these are
set forth in the following pages.
Characters of the Sedimentary Rocks.
The sedimentary rocks of the Newark system, as is generally
known, are chiefly fine-grained red shales, with some sandstones
and conglomorates (Brunswick), and, at some horizons, thick
black argillites which do not readily split into thin layers
(lyockatong). Coarse conglomerates occur not only nesir the
base of the series, but also near the top and at various intermedi-
ate horizons. Heavy-bedded- sandstone also occurs at various
levels, chiefly, but not exculsively, in the lower part (Stockton).
Associated with the black argillites are gray and green flagstones,
and occasionally thin layers of very calcareous shale; but the
great mass of the formation in its most characteristic phase is a
soft red shale, in which occasional layers of purple, green, yellow
and black shales occur.
"Ripple-marks, mud-cracks and raindrop impressions occur at
many horizons. In some quarries impressions of leaves and
stems of trees, or the stems themselves, are not infrequently
found. Occasionally slabs are found bearing the foot-prints of
reptiles and other vertebrates which wandered over the soft mud-
flats while these beds were in process of accumulation.'' ^ Cross-
bedding, or plunge-and-flow structure, and rapid variations of
texture in the individual beds are also common characteristics of
the coarser sediments.
Sources of the Sediments.
Many of the sandstones, particularly the coarser ones, are
feldspathic and have numerous flakes of mica, all of which are
^Kiimmel, Ann. Rep. of State Geologist, 1897, p. 42.
102 . THE STATE GEOLOGIST.
products of the disintegration of granites and gneisses, with little
decomposition. The conglomerates sometimes contain gneissic
pebbles, but most of them are composed of fragments broken from
Paleozoic quartzites and limestones. The purer sands are doubt-
less residual grains from decomposing granites and gneisses and
from crumbling quartzites. The shales are consolidated mud-
beds, derived from residual soil of limestones and from the de-
composing feldspars of granites and gneisses. All of these ma-
terials were washed down from the adjacent Highlands, the dis-
integration and decay of the underlying rocks renewing the soil
as it was gradually removed by erosion and carried away by the
streams.
It is not necessary to suppose that the lands were covered with
an unusual thickness of such materials, for the period of dego-
sition was of vast duration. We need only recall how slowly
such sediments are accumulating in bays, lakes and flood-plains
of rivers at the present time in order to form some conception of
the immense periods of time represented by the Newark strata,
which are probably more than two miles thick. We must further
recognize the probability that there were long intervals during
which deposition was retarded or possibly suspended alto-
gether. The renewal of the soil keeps pace with the ordinary
rate of erosion in hills and mountains of moderate slope, but the
conglomerates of the Newark show that mountain torrents often
rent the solid bed-rocks asunder and contributed their fragments
in the forms of pebbles and bowlders to the accumulating sedi-
ments.
ORIGIN 0^ THE SEDIMENTS.
In considering the question of origin, it is necessary to bear in
jnind the distribution of the Newark rocks in adjoining regions
along the Atlantic coast, as shown in Fig. i, and particularly to
note that this belt in New Jersey is part of a long strip that
skirts along the region of the crystalline Highlands from Haver-
straw, New York, southwestward through New Jersey, Penn-
sylvania, Mjaryland, and far into Virginia. This is the most ex-
ORIGIN NEWARK ROCKS. 103
tensive single area, but the others are much like it in form and
characters of sediments.
The Tidal Estuary Hypothesis,
It has long been customary for geologists to speak of the New-'
ark beds as having been deposited in "broad, shallow estuaries,
whose shores were laid bare by the retreating tide, and in which
the varying currents alternately deposited coarse and fine ma-
terials." The ripple-marks, sun-cracks, raindrop impressions,
and tracks of animals were regarded as proof that the strata were
once low beaches or mud-flats, laid bare at low tide, where land
animals came in search of food.^ "At the beginning of Newark
time, therefore, we must conceive of a broad, shallow estuary ex-
tending across the northern part of what is now the S'tate of New
Jersey. * * * The streams from the bordering land areas
carried into the estuary rock debris which was distributed over the
bottom by the waves and tidal currents. The waves beating
against the shore contributed their quota of material. * ♦ *
The sudden alternation from shale to conglomerates, the rapid
thinning out of individual layers, the presence of ripple-marks,
raindrop impressions and mud-cracks indicate that these beds
were formed in close proximity to the shore line. Sticks and
trunks of trees were frequently imbedded in the layers of sand and
gravel. These deposits were formed quite widely over the floor
of the estuary, near the middle as well as near the present border,
since the Hopewell and Flemington faults bring similar beds to
the surface." * ♦ *
"Frequent mention has been made of the fact that the Newark
beds are shallow-water deposits throughout their entire thick-
ness. At no time, apparently, was the water of the estuary so
deep that the outgoing tide did not expose broad areas of sand or
mud. It follows from this that there must have been a progres-
sive subsidence in the estuary during the deposition of these
*Kummel, Ann. Rep. of State Geologist, 1897, p. 139; Newberry, Mon. U.
S. Geol. Sur., XIV, 1888, p. 5 ; Russell, Bull. U. S. Geol. Sur. No. 85, p. 45-
I04 THE STATE GEOLOGIST.
beds, since their thickness is to be measured by thousands of feet.
The subsidence went on pari passu with the deposition of the
sediments, so that the shallow water conditions prevailed con^
tinually," ^
This interpretation was regarded as satisfactory by geologists
generally less than a decade ago, and it is still to be found in the
current text-books. »
The Lake Basin Hypothesis,
In connection with the estuary hypothesis described above, or
as an alternative to it, the supposition that some areas of Newark
rocks were formed in lakes has been advocated. The gradual
subsidence is assumed in this case, as in that of estuaries, and the
concurrent filling up by sediments so as to maintain a constant
alternation of shallow water and bare mud and sand flats.
Otherwise the conditions of the lake hypothesis are identical with
those stated above. ,
Objections to the Foregoing Hypotheses.
It is now beginning to be realized ( i ) that impressions made
on soft muds or sands at low tide are effaced by the next suc-
ceeding high tide or are preserved only under exceptional condi-
tions; (2) that the features once ascribed only to tidal shore, or
littoral, deposits are much more characteristic of alluvial sedi-
ments on land; and (3), finally, that the area of such littoral de-
posits is much smaller than that of river-made deposits above
tide, and that they should consequently be comparatively rare in
the sedimentary records of the past.^ It is seen also that the
current hypotheses offer no satisfactory explanation of the alter-
nation of coarse sands and gravel with layers of fine mud near
the middle as well as along the shores of the estuary or lake.
Furthermore, the pari passu subsidence, keeping pace with the
rate of deposition, which must be assumed in order to provide
* Kiimmel, loc. cit, pp. 13^143. The italics are not used in the original.
* Relative geological importance of continental, littoral and marine sedimen-
tation. Joseph Barren, Jour. Geol., XTV, 1906, pp. 316, 430, 524.
ORIGIN NEWARK ROCKS. 105
continuous shallow water conditions, is highly improbable when
extended over the immense period of time necessary for the ac-
cumulation of sediments many thousands of feet thick. The en-
tire absence of marine fossils ia inconsistent with the estuary-
hypothesis, while the presence of land plants and animals, with
only occasional fresh-water forms, is quite unfavorable to any
extensive application of the lake hypothesis.
These difficulties were fully realized by Professor J. D. Dana,
who says : "It is not possible that the sandstone formation was
made during a general submergence and in a great common body
of water; for there is nothing marine about it in fossils or in
structure; and fresh waters for the work could not have spread
over the region of hills, ridges, and valleys under any probable
circumstances.''
The Hypothesis of Orographic Valleys.
Professor Dana points to the facts that the Nova Scotia and
Connecticut Vklley belts of these rocks lie in the same troughs
that had received sediments through a large part of Paleozoic
time, and, further, that "the parallelism of the belts to the moun-
tain ranges of the continental border is close,, * * * ^s
if occupying orographic valleys of the' Appalachian mountain
chain.'' These orographic valleys he conceives to have been oc-
cupied by great broad rivers that made "conglomerates where
the water had great velocity, sandstones in gentler currents,
shales in the sluggish waters, and beds of vegetable debris for a
coal bed where the conditions were those of a great marsh."* * *
"Where were the sources and what the directions of the rivers
over the higher lands from New York to North Carolina, which
supplied so generally granitic sediments instead of quartzose
sands and fine clays, are questions not easily answered." * * *
"The river or waters of the time flowing southward, just west
of the site of New York City — where now flows the Hudson —
were 25 miles wide, as the breadth of the Triassic of the region
shows, and they had sources evidently in the nearer mountains
to the north, west, and south. These sources were probably in
the Highlands and other ridges of crystalline rocks. The waters
io6 THE STATE GEOLOGIST.
and sediment certainly did not come from the Catskill Mountains
to the north nor from the Alleghanies to the west/'^
Objections to the Orographic Valley hypothesis.
The width of Newark strata opposite New York city is only an
unknown fraction of their former extent, for the northwestern
border is here determined by a fault, the Cretaceous overlaps on
the southeast, and the monoclinal structure of the remainder
shows that yast amounts have been removed by erosion. Assum-
ing flood-plains of such proportions it is not remarkable that
the sources and directions of the rivers by which they were
formed should present difficult questions. The difficulty is vastly
increased by the fact that the drainage of the Catskills and the
Appalachian Mountains passed off in other directions, since the
Newark sediments were derived from the older crystallines.
A Piedmont Plain hypothesis.
Four prominent conditions are to be considered in discussing
the origin of the Newark sediments of New Jersey and the
Atlantic region generally; namely (i) the evident derivation of
most of the material from regions of crystalline rocks; (2) the
strongly marked evidences of deposition by rivers, with only local
lakes, and possibly estuaries; (3) the occurrence of these rocks
in well-defined, long, narrow, basin-like areas parallel to the
main structural lines of the Appalachian Mountains; (4) the
wide-spread occurrence of fossil land plants and footprints of
land animals, with bituminous shales in many localities and coal
beds in Virginia and North Carolina, in contrast with the limited
local areas of fossil fishes and crustaceans, which may be either
brackish or fresh-water forms.
These conditions are believed to be fully met by the hypothesis
of river deposition across a relatively smooth piedmont plain
* Manual of Geology, 4th ed., 1895, p. 743.
ORIGIN NEWARK ROCKS. 107
fronting the newly uplifted crystalline foreland, or protaxis, of
the Appalachian Mountains, with concurrent synclinal wrinkling
and down- faulting of the long basin-like areas in which the
present remnants of these rocks have been preserved.
During the Appalachian uplift and for long periods afterwards
the crystalline protaxis must have remained the greit divide be-
tween the waters of the Gulf drainage and those that passed
directly into the open Atlantic. Numerous short but vigorous
streams brought down the debris of the disintegrating and de-
composing granites, gneisses, and metamorphic sediments of
earlier Paleozoic age, and deposited them in coalescing alluvial
fans across the smoother plain of the crystalline Piedmont. Oc-
casional downward movements, of warping or faulting, gave
opportunity for local thickening of the deposits along the belts
affected.
According to this conception the Piedmont plain was of much
greater width than the present areas of the Newark strata, and
it probably merged into coastal marine and estuarine deposits
along the eastern border. As a rule, however, the deposits were
probably not very thick except in the elongated areas of progres-
sive or intermittent deformation. Hence when the whole Pied-
mont was eventually uplifted the relatively thin mantle of debris
was removed by erosion from the greater part of the region, and
only those narrow belts that were protected by down-warping
and faulting between adjacent areas of the harder crystalline
rocks have been preserved to the present time.
The northwestward tilting caused the displaced strata to be
beveled off across the upturned edges and brought up again the
crystallines along the southeastern border. These crystallines
form the hills that everywhere skirt the eastern boundary of the
New York- Virginia area except where it crosses New Jersey, and
similar conditions are found in the various other belts of these
rocks along the Atlantic slope. Across the narrowest part of
New Jersey, however, these east^n crystallines were again so
greatly worn down and depressed that they were buried by the
later Cretaceous sediments, except a small area of gneisses now
found in the vicinity of Trenton. On account of these over-
THE STATE GEOLOGIST.
lapping Cretaceous sands and clays, the exact southeastern limit
of the Newark formation from Trenton to Staten Island is not
known.
The generally scant vegetation and the highly oxidized, iron-
stained sediments that prevail in the Newark strata strongly sug-
gest an arid climate. In this case the deposition of the sediments
was perhaps as much due to loss of volume as to change of slope
in the contributing' streams, as in the arid piedmont plains of
southern California and elsewhere in the western United States
to-day.
Late in the period of deposition of the Newark strata con-
tinued depression of the elongated narrow belts along the Pied-
mont plain, by folding and faulting, eventually gave rise to
fissures through which repeated eruptions of lava overspread
considerable areas of the deposits and great intrusive sheets, or
sills, of similar lava were injected between some of the deeply
buried strata.
GEOI.OGIC REI.ATI0NS OV^ THE TRAP ROCKS.
The distribution of the trap rocks, which constitute more than
one-tenth of the total Newark area of the State, is shown on the
accompanying map, PI. XXVIII. Davis, Darton, Kiimmel and
other workers in this field have shown that these rocks are of
igneous origin and were formed during the latter part of Newark
time. They represent both lavas that reached the surface and
became extrusive^ and also lavas that penetrated the sediments
and became intrusive. Their geologic relations have been de-
scribed in detail by Kiimmel in a previous report of the Sur-
vey.^ Supplementary to that report, attention is here directed
to certain further correlations of the various trap masses and
to some difference of interpretation of observed relations.
Relations of the Extrusives,
The Watchung flows. — The Watchung Mountains and the
various trap ridges west of them are all extrusive sheets, or lava
'Ann. Rep. State Geologist of N. J. for 1897, pp. 58-99-
ORIGIN NEWARK ROCKS. 109
flows, as are also the semi-circular ridges near New German-
town and Sand Brook. The grouping of these sheets in the
west-central portion of the area, where no intrusives occur, and
their almost total absence from the areas of intrusives to the
northeast and southwest are characteristics which are forcibly-
impressed by the map, PI. XXVIII. The former is the area of
uppermost and, therefore, latest Newark strata, while the deep-
seated intrusive masses have been laid bare only where these later
strata have been removed to great depths by erosion.
The thinning out of the lowest extrusive lava sheet north of
Somerville apparently causes the narrowing down of First
Mountain and its final termination at Pluckamin. Second Moun-
tain recurves in hook form until cut diagonally across by the
great boundary fault near Bernardsville. This fault continues
northward to the State line and terminates the curved extremities
of all three of the extrusive sheets beyond Pompton. The re-
curved ends of these ridges are the result of the Passaic Basin
syncline, the shallow boat-like structure into which the strata
and the trap sheets of this region have been bent.
Packanack and Hook mountains, Riker Hill and Long Hill,
by their structure and attitude with reference to each other, are
quite probably parts of a single extrusive sheet. As to their ex-
trusive character there can be no question, and they are all much
thinner than the great flows that constitute First and Second
mountains. Their disconnected character may be explained
upon the hypothesis that the eruption was slight and did not com-
pletely cover the area, .so that there were tongues, or project-
ing lobes of lava, or there may have been several small eruptions
from independent vents or fissures. On the other hand, tKeir dis-
continuity may be due to preglacial or glacial erosion, the por-
tions that were most worn down being buried by the later de-
position of glacial drift and river sediment that now cover much
of this region.
All of these hypotheses seem to be consistent with the facts
so far as known, but further knowledge of the strata now buried
beneath the broad alluvial flood-plains of the upper Passaic River
may be necessary in order to determine which is the correct in-
8 GEOL
no THE STATE GEOLOGIST.
terpretation. Under the circumstances, one of the hypotheses of
scant eruption seems most probable.
The semi-circular trap ridge near New Vernon is a thin extru-
sive sheet exactly similar to that of Long Hill; and, in fact,
it seems quite certainly to be the upturned western border of the
same sheet. The structure of the shales within the trap ridg^
shows that it has been brought up by a dome-like anticline, or
upward fold, which has thrown the outcrop far enough eastward
to prevent its being cut off by the great fault along the adjacent
border of the crystalline Highlands.
The Double Crest of Second Mountain, — The striking and per-
sistent double crest of the curved southwestern part of Second
Mountain (Fig. 2) has been explained^ as the result of a curved
longitudinal fault parallel to the present outcrop of the trap sheet.
While entirely consistent with the facts so far as at present
known, the probability of such a coincidence is so extremely
small that, in the absence of positive proof of faulting, this
hypothesis must be regarded as exceedingly doubtful. Brief dis-
cussions are here given of (i) the facts requiring explanation,
(2) the interbedded shale hypothesis, (3) the curved longitudinal
fault hypothesis, and (4) the hypothesis here advanced, namely,
that of a double flow of lava with intercurrent warping. The last
is somewhat more fully presented and its bearing upon subsequent
geologic history discussed. The others are summarized from
Kiimmel's report, above cited.
(i) The facts requiring explanation. — ^The width of outcrop
of the trap along Second Mountain varies greatly. The hook-
shaped southwestern portion is broader than elsewhere, and for
a distance of 17 miles the crest is distinctly double. In the
intervening valley shale has been found in a number of places,
either in well-borings or at the surface. At both ends of the
ridge, however, the crest is single, and no shales are found inter-
bedded in the trap in the gorge of the Passaic River at Little
Falls. In a well at Mount St. Dominic Academy, at Caldwell,
the following section was found: Glacial drift, 100 feet; trap
^Darton, Bull. U. S. Geol. Survey No. 67, p. 22. Kummel, Ann. Rept. of
State Geologist for 1897, p. 125.
ORIGIN NEWARK ROCKS.
Ill
rock, 775 feet ; total 875 feet ; shale at the bottom. A well bored
for Mr. KeanQ on the inner crest of Second Mountain, near East
Livingston, and 3 miles from the well at Caldwell, furnished
the following section: Soil, 5 feet; trap rock, 90 feet: brown
sandstone, 51 feet; trap rock, 381 feet; total, 527 feet. Both
wells are in such locations as to pass through an interbedded
112 THE STATE . GEOLOGIST.
layer of sediments, if such existed. Over the country between the
two crests, Darton found red shale fragments, which he regarded
as portions of underlying sediments.
(2)"-The-4nterbed<ied shale hypothesis. — Kiimmel considered
the hypothesis that Second Mountain is composed of two succes-
sive flows of lava separated by a continuous stratum of sediments,
but rejected it for the following reasons: (a) the crest is single
at both ends of the ridge; (b) no trace of shale is found at either
locality; (c) the Little Falls gorge and the Caldwell well show
no shale. The "brown sandstone" reported from Mr. Keane's
well he regards as probably a red-brown variety of trap.
(3) The fault hypothesis. — Under the apparent necessity of
choosing between the interbedded shale hypothesis, described
above, and that of a f^ult which conforms to the present outcrop
around the sharply recurved southwestern extremity of Second
Mountain, both Darton and Kiimmel adopted thejatter, in spite
of the fact that "no direct evidence of faulting beyond that
furnished by the topography — the- repetition of the beds — ^was
found." "Indirect evidence derived from a study of the width
of the outcrop of the trap and the apparent thickness along dif-
ferent section lines," may be summarized as follows : On the as-
sumptions (a) that there was no deformation in the intervals
between the lava flows (nor accompanying the flows) ; (b) that
sedimentation was uniform throughout the area; and (c) that
the lava sheets are approximately of uniform thickness, their
bases must have been originally parallel. Allowing for known
faults this is still true of First and Second mountains ; but from
the base of the Second to that of the Third (Long Hill, etc.), is
a distance that varies greatly in different sections, and the ap-
parent differences are greater where the double crests of Second
Mountain are most marked. This variation is ascribed to fault-
ing, which Darton assumed further to be confined to the present
areas of trap outcrop.
Kiimmel points out several very obvious defects in the above
reasoning: (i) that any or all of these varidus assumptions
may be incorrect; (2) that there is no conclusive reason for sup-
posing that faulting is restricted to the trap areas of the present
ORIGIN NEWARK ROCKS. 113
surface, and (3) that variations in thickness of either the trap,
of Second Mountain or of the overlying shales would vitiate the
conclusions. Notwithstanding these elements of uncertainty and
improbability, however, the estimates based on the above assump-
tions are regarded as "indicating quite clearly that some faulting
has occurred," and as "strengthening the argument derived from
the double crest." Hence the conclusion that "it is safe to assume
that Second Mountain is traversed for much of its extent by a
curving longitudinal fault."
(4) A hypothesis of double flow with intercurrent warping. —
The explanation here advanced is believed to be consistent with
all the known facts and to involve no improbable assumptions.
It is practically the interbedded shale hypothesis, described above,
freed from the restrictions of stability and uniform sedimentation
in the intervals between the lava flows.
The present condition of the Newark rocks throughout eastern
North America shows that they have been subjected to univers«nl
deformation, and as yet there is no known means of defining the
exact stage in their history at which the disturbing movements
began. The slightest warping of the surface at any stage of the
sedimentation would have its inevitable effect on the thickness
and distribution of the subsequent deposits. This is specially true
of shallow water and continental formations, such as these
Newark beds are generally conceded to be.
The proposed hypothesis to account for the conditions abo\^
enumerated in Second Mountain may be stated as follows : After
the eruption of the First Mountain trap sheet and the deposition
of some 600 feet of overlying shales and sandstones, a second
eruption occurred, forming a lava sheet averaging probably 500
feet thick over the same region. With this outflow began a
gradual depression of the southern axial region of the Passaic
Basin syncline — the region from Somerville northeastward. As
a result subsequent deposits were concentrated in this region,
tending to build it up to the level of the adjoining area, but not
succeeding entirely in this before deposition was again ipter-
rupted by eruption. Another lava sheet of about 500 feet average
thickness was spread over the region, but not uniformly, nor even
114 THE STATE GEOLOGIST.
approximately so, as the preceding flow had been. Over the
shales in the depressed area the maximum thickness was at least
800 feet, while in the adjoining- r^ons where it rested on the
unburied flanks of the previous flow it did not exceed 200 feet.
Thus the two flows merged into one on the sides of the incipient
ORIGIN NEWARK ROCKS. 115
syncline, but were separated by a thin stratum of shale in the
depression. (Figs. 3 and 4).
fig. 4.
Sediments. Trap sheets.
Cross section on line A-B, figure 3.
When the edges were later upturned to the forces of weather-
ing and erosion the soft shales quickly wore away to a lower level,
thus forming the continuous valley curving conformably with
the outcropping edges of the adjacent traps above and below.
The valley between the double crests of Second Mountain is,
therefore, considered to be exactly comparable to Washington
Valley between First and Second mountains. It is shallower and
the escarpment of the overlying trap outcrop is less pronounced
because of the limited thickness of the interbedded shales.
(Figf. 4).
Evidence of continued depression in the same synclinal region
is found in the sediments between Second Mountain and the over-
lying trap sheet of Long Hilll. There is a decrease of one-fourth
in the thickness of the intervening shales at Madison as compared
with those at Millington, and a much more rapid thinning out
toward the west. The trap sheet of Long Hill is also thicker
about Millington, but this may not be due to original inequality
of the surface upon which it was laid.
The Sand Brook and New Germantown Bxtrusives. — ^These
two small areas deserve special notice, because they have pre-
served remnants of trap sheets that were doubtless once much
more extensive. Eiach is but the eastern spoon-shaped end of a
syncline that has been cut off by a fault to the west, and each con-
tains remnants of two separate masses of trap of exactly similar
forms and relations. The larger mass in each case outcrops in a
westward-pointing crescent and curves downward beneath the
shales within. The smaller caps a rounded hill between the
points of the crescent, thus resting upon the sediments that overlie
ii6 THE STATE GEOLOGIST.
the synclinal sheet below. ^ At New Germantown this upper
fragment is separated, doubtless by erosion, into two small dis-
connected masses.
Here we have remnants of two lava flows, separated by several
hundred feet of shales, in exactly the same manner as the sheets
of the Watchung Mountains. Kiimmel^ has shown, from the
structure of the region, that they are "in a general way contem-
poraneous with the Watchunjg flows," but concludes that "there
is no evidence that they are parts of the same flows." It may also
be stated, on the other hand, that there is no evidence that they re-
present separate flows, and it may be shown that they probably
do not. The lava sheets whose eroded edges form First and
Second mountains, are certainly only remnants of the original
flows, yet they still occupy a region about 12 by 40 miles in* extent.
Considering their great thickness in the vicinity of Bound Brook
and Somerville, it is altogether probable that they once extended
half as far again to the southwest, which would carry them be-
yond the most distant remnants at Sand Brook. In this case rem-
nants of the eroded Watchung sheets, if of earlier origin, would
now underlie those of New Germantown and Sand Brook, and
would outcrop in larger curves to the east of these localities. On
the other hand, unless these small remnants are parts of very
limited local flows, they would also have overlapped the present
area of the Watchung sheets. This is especially true of the New
Germantown trap, which is only 6 miles distant. In this case their
edges would appear in the shales beneath and southeast of the
Watchung ridges, if older, or above, in the Passaic Basin syn-
cline, if younger.
Since it is clear, then, from the stratigraphy of the region, that
the New Germantown and Sand Brook traps are approximately
^ Kiimmel, finding the contacts of these small . inner trap masses so ob-
scured by soil-covering at both localities that their relations to the sediments
could not be observed, did not commit himself as to their extrusive or intru-
sive character. (Ann. Rep. of State Geologist of N. J., 1896, 1897.) The
absence of metamorphism in the shales was noted, however, and the trap
is quite vesicular, so that there can be little doubt that the interpretation
given above is correct.
'Ann. Report of State Geologist of N. J., 1897, p. 98.
ORIGIN NEWARK ROCKS. 117
contemporaneous with the Watchtmg flows, the conclusion is al-
most imperative either ( i ) that they are exactly contemporaneous
and parts of the same sheets, or (2) that the present remnants
are fragments of small local outpourings of earlier date than the
Watchung flows. Of these the former conclusion seems the more
probable, and on this basis the New Germantown and Sand
Brook traps are correlated with the trap sheets of First and
Second mountains.
It should not be overlooked, however, that there is still another
possible interpretation, namely, that neither the New German-
town and Sand Brook traps, on the one hand, nor the trap sheets
of the Watchungs, on the other, have ever extended far enough
beyond their present boundaries to overlap the regions now
occupied by the other. In this case their relationships can be
-established only by the stratigraphy ; and it is impossible, in the
bomogeneous red Brunswick shales of this region, to attain more
than an approximate correlation, as quoted above from Kiimmel.
Even in this case, however, it is more probable, a priori, that the
smaller eruptions took place contemporaneously with the greater
volcanic activity in the adjacent area than at other times.
Relations of the Intrusives,
The sills, or intrusive sheets, include the Palisades to the
northeast, along the Hudson River, and the trap ridges of Rocky
Hill and of Pennington, Baldpate, Sourland, and Cushetunk
mountains in the southwestern part of the area. Other intrusive
masses, often closely associated with these, are more of the na-
ture of round bosses, such as Mount Gilboa and the Snake Hills,
or in the form of thin dikes, like that which crosses the Mill-
stone River west of New Brunswick, and numerous shorter ones
in other localities.
The Palisades, Rocky Hill, Sourland Mountain, Byram. — Both
the position and direction of the main outcrop of the Rocky Hill
trap strongly suggest that it is a continuation of the Palisades
sill, as pointed* out by various former observers. Darton^
*Bull. U. S. Geol. Survey, No. 67, 1890, p. 39.
ii8 THE STATE GEOLOGIST.
states that "the interval between the Staten Island outcrops and
those at Lawrence Brook is mostly covered by Cretaceous clays,
under which the Newark is known to extend for some distance,
and it is possible that the trap continues southward and is simi-
larly overlapped." A number of facts that have been gathered
from deep-well borings and river dredging in the intervening ter-
ritory now make it practically certain that this supposition is
true. (See PI. XXIX.)
On Staten Island, shallow wells show the continuation of the
Palisades sill southward to the vicinity of Fresh Kills, opposite
Carteret, New Jersey. Three wells at the car works near Car-
teret (a, PI. XXIX), after passing through sand and' clay 60 and
90 feet, respectively, struck hard rock that "dulled the drill in 15
minutes," and reported by the contractor as "evidently trap
rock."^ At Boynton Beach (b, PL XXIX), 3 miles southwest-
ward, the following well-section was found:
Clay, sand and gravel, 75 feet.
Red shale, 3 "
Trap rock, 70 "
Red sandstone, 2 "
Trap rock, 7 "
Total, 157 "
Evidently a sandstone inclusion in the trap was here en-
countered, similar to those found at numerous points northward
along the Palisades.^ Two wells bored at Maurer station (c, d,
PI. XXIX), 2 miles north of Perth Amboy, found trap under
sand and clay 64 feet and 78 feet deep, respectively.^ In a well
drilled at M. D. Valentine & Brothers Company's works, three-
fourths of a mile south of Woodbridge {e, PI. XXIX), at a depth
of 56 feet hard rock was found. At first this was supposed to be
trap, but it afterwards proved to be indurated shale and sand-
stone. These are undoubtedly the metamorphic sediments over-
■Ann. Rep. State Geologist of N. J. for 1896, p. 199.
•Ann. Rep. State Geologist of N. J. for 1904, p. 265.
'Ann. Rep. State Geologist of N. J. for 1904, p. 268; 1895, p. 93.
ORIGIN NEWARK ROCKS. 119
lying the trap silL^ Near Keasby (/, PI. XXIX), on the Rari-
tan River, 2 miles west of Perth Amboy, hard rock, probably
trap, was encountered under 72 feet of sand and clay.^
In dredging- and blasting operations in the Raritan River, a
mile below Martins Dock (g, PI. XXIX), a reef of indurated
shale 500 feet wide was found crossing the river in a northeast-
southwest course, 5 to 12 feet below low water. No trap rock
was found, but it cannot be doubted that this shale corresponds
to the belt of metamorphic sediments everywhere skirting the
great intrusive sills of trap.^ Also 2 miles southeast of Deans
station (A, PI. XXIX), on the Pennsylvania Railroad, near Fresh
Ponds, a bored well encountered trap rock under 60 feet of clay,
unquestionably the buried margin of the Rocky Hill mass, which
outcrops about Deans. ^
Mr. W. R. Osborne, the contractor, also reports that trap was
encountered in a bored well near the old Baptist church at South
River, at a depth of 130 feet.
The trap dikes east, south and west of New Brunswick bear
about the same relation to this buried extension of the Palisades
sill as do those of the Snake Hills, Arlington, Granton and Bo-
gota to its prominent outcrop farther northward. (Pls.XXVIII
and XXIX.) As pointed out in the discussion of the copper ores,
those of New Brunswick and Newtown occupy the same relative
position with reference to this covered part of the sill that the
ores of Arlington and Glen Ridge hold with regard to the
Palisades.
The Palisades trap lies much lower in the sedimentary series
than that of Rocky Hill, but the latter is highest at its western
extremity and rapidly descends to lower horizons to the east,
where it finally passes under the Cretaceous cover. A continued
drop would readily unite it with the Palisades sill on Staten
Island. Furthermore, the Rocky Hill trap increases in thickness
^Ann. Rep. State Geologist of N. J. for 1895, p. 93. This locality was
erroneously reported as i54 miles southwest of Woodbridge.
'Ann. Rep. State Geologist of N. J. for 1898, pp. 131, 132.
"Ann. Rep. State Geologist of N. J. for 1882, p. 59; 1895, p. 93.
*Ann. Rep. State Geologist of N. J. for 1900, p. 159.
I20 THE STATE GEOLOGIST.
eastward from its narrow outcrop near Hopewdl, and the same
thickening is continued in the Palisades sill northward from
Staten Island and Bergen Point. As it passes further northward
into New York the Palisades trap again becomes thinner, and its
recurved extremity rises rapidly through the sediments west of
Haverstraw until it reaches almost the top of the series. Their
relations to the sediments are, therefore, entirely consistent with
their continuity.
The intrusive trap masses of Pennington and Baldpate moun-
tains are doubtless lobe-like protrusions of the same Palisades-
Rocky Hill sill, as suggested by Darton, and all probably merge
into one continuous sheet at no great depth. The irregular forms
of Pennington and Baldpate mountains and the northeastward
arm of Rocky Hill all indicate subterranean branching of the in-
trusive lava in this region.
The relations of the Sourland Mountain trap, brought up by
the Hopewell fault in a repeated series of strata dipping north-
westward, strongly suggest that it is also a part of the Palisades-
Rocky Hill sill. (See section, PI. XXVIII. ). If depressed some
6,000 feet, the approximate throw of the fault, it would fall into
line with the subterranean continuation of the trap of Rocky Hill,
Pennington Mountain and Baldpate Mountain. In a similar
manner Mount Gilboa, above Lambertville, and the smaller iso-
lated trap mass at Byram, each lying on the upthrow side of a
fault that repeats a portion of the sedim.entary series, may reason-
ably be regarded as fragments of the same sill brought up from
near its thinner northwestern border.
Thus, according to the view here advocated, the intrusive trap
masses outcropping in the Palisades, in Rocky Hill, in Penning-
ton, Baldpate and Sourland mountains, in Mount Gilboa, as well
as the mass at Byram, are all to be regarded as probably parts
of one continuous intrusion, separated by the Cretaceous overlap
in the case of the Palisades and Rocky Hill, by lobe-like subter-
ranean branching in Pennington and Baldpate mountains, and
by faulting in the other cases.
There is a widespread impression that the Palisades sill drops
steeply downward across the strata from its western margin, and
geologists have generally so represented it in cross-sections. This
ORIGIN NEWARK ROCKS. 121
impression is doubtless due to the preponderating influence of
three easily accessible upper contacts that do show such conditions
for 20 or 30 feet. These are in the West Shore and N. Y. S. &
W. Railroad tunnels through the Palisades, and the West Shore
tunnel near Haverstraw. In two of these localities (the West
Shore tunnels) both the topography and the boundaries of the
trap outcrop show clearly that the relations are exceptional ; but
they have been emphasized by detailed descriptions and illustra-
tions in the reports, while the conformable contacts have very
naturally been passed over with a simple statement of the facts.
Kiimmel^ has described four conformable upper contacts, two
unconformable, and two doubtful, while of the under contacts
along the Hudson River only three are conformable, fifteen are
unconformable, and one is doubtful. Yet, in spite of the numer-
ous irregularities of the under surface of the trap, and its con-
stant shifting from one horizon to another, it is evident that in
a broad general view it is approximately conformable to the
sedimentary strata. Even less irregularity is known in its upper
surface, but probably, if an equal number of contacts could be
observed, the conditions would be found about the same. At
any rate, there seems to be no good reason why these upper con-
tacts should be regarded as showing the -fissure arising from the
deep-seated origin of the lava, when it is perfectly clear that simi-
lar contacts beneath the Palisades are not susceptible of such
interpretation.
Off-shoots of the Palisades SilL — Snake Hill and Little Snake
Hill are two knobs of trap which stand up prominently out of
the Hackensack Meadows at distances of a mile and three-eighths
and I mile, respectively, from the foot of the western slope of
the Palisades. If the Palisades trap continues approximately con-
formable to the sedimentaries under the meadows, as it does
along the Hudson River, it probably does not lie more than 1,600
feet and 1,300 feet, respectively, below the outcrops of the Snake
Hills. These have, therefore, been very naturally regarded as
off-shoots from it. In other words, they are less than one-fourth
as far from the underlying sill as from its nearest outcrop, and it
*Ann. Rep. State .Geologist for 1897, pp. 62-72.
122 THE STATE GEOLOGIST.
would be difficult to construct.a section on the basis of our present
knowledge without connecting them with the Palisades.
The trap dike and sheet that form the small hill just north of
Granton are about 800 feet from the nearest outcrop of the
Palisades trap, but they cannot be more than 200 feet above the
underlying portion of it. They must also be regarded, therefore,
as an off-shoot from the Palisades.
The dikes and sheets at the Arlington copper mine are 4 miles
from the Palisades at Jersey City and 6 miles from the trap of
First" Mountain at Montclair. Since the latter is a perfectly con-
formable sheet, dipping westward with the sedimentaries on
which it rests, and the former is approximately conformable, with
a similar dip, it seems probable that these dikes are also off-shoots
of the Palisades sheet, which, with an average westerly dip of
12 degrees, would lie some 8,000 feet below.
In like manner the dike at Bogota, the numerous dikes east,
•south, and west of New Brunswick, and those scattered over the
region northwest of Sourland Mountain are most readily ex-
plained as thin off-shoots from the same sill. In fact some of
these in the last-named area have been traced by Kiimmel to a
direct connection with the great intrusive sheet at the outcrop,
and there is little room to question that the others are of the same
character.
Cushetunk and Round mountains, — The trap masses of Cush-
'Ctunk Mountain and Round Mountain are intrusives of the same
character as the great Palisades-Rocky Hill-Sourland Moun-
tain sill, and may represent a contemporaneous upward protrusion
of the same magna, but there is no means of definitely determin-
ing this question. There is, however, an interval of little more
than 3 miles between Round Mountain and the dikes about
Flemington, which are undoubtedly offshoots of the Sourland
Mountain trap. Whether belonging to the same period of in-
trusion as these or not, it does not seem improbable that the up-
ward movement of the magma was stopped and possibly its
lateral extension determined by the overlying extrusives of the
Watchung Mountains which have since been removed . from this
region by erosion. It is shown, in discussing the relations of
the New Germantown and Sand Brook synclines, that the trap
ORIGIN NEWARK ROCKS. 123
sheets of First and Second mountains probably once extended
over this region, and the known structures would carry them
across just over Cushetunk Mountain.
The mutual relations of the various disconnected outcrops
about Cushetunk and Round mountains are open to question.
The structure is complicated and there are not sufficient outcrops
of the sedimentary strata available in the vicinity of the trap
masses to make satisfactory conclusions possible — ^not at least
without considerably more minute and painstaking search over
the area than it has yet been possible to make. Darton^ concluded
that all the masses in this vicinity had once probably constituted
one wide intrusive sheet, "considerably flexed, and with the
form of its present outcrops mainly determined by the removal of
the trap from the crests of the anticlinals.'' Kiimmel,^ on the
other hand, after thorough examination of the surrounding sedi-
mentaries, concluded that the curving outline of Cushetunk
Mountain "is not due, primarily, at least, to an anticlinal or syn-
clinal fold in the shales, but to the curving fracture through which
the trap has come.'' As to Round Mountain, he thought it prob-
ably intrusive, but did not regard the evidence as complete as in
the case of Cushetunk Mountain. Metamorphic effects observed
in the sediments on the slopes of the mountain in this investiga-
tion leave no doubt as to the intrusive character of the
adjacent trap, and this is in harmony with its prevailingly coarse
granitic texture. As to the relations of Round Mountain, the few
facts observed seem to favor Darton's conclusion that it "lies in a
well-defined synclinal or spoon, and is separated from Cushetunk
by a local anticlinar' from which the trap has been removed by
erosion.
Origin of the Trap Rocks.
The following statements in regard to their origin, while fol-
lowing in the main the conclusions of previous investigators,
differ in some important details, particularly as regards the char-
acter of Second Mountain and the conditions of intrusion.
* Bulletin U. S. Geological Survey No. 67, p. 64.
' Annual Report of the State Geologist for 1897, p. 76.
124 THE STATE GEOLOGIST.
Origin of the First Mountain Extrusive,
Eventually when weighed down under some 10,000 feet of
clays and sands, in the New Jersey region, continued subsidence
along the narrow belts of the Piedmont resulted in deep-seated
fractures through which a great flood of lava was forced up.
Breaking its way through the weak layers of the overlying sedi-
ments it spread in a broad sheet about 600 feet thick over the
area of the present Watchung Mountains and beyond. How far
beyond there is no present means of estimating. A remnant of
this sheet remains, and its outcropping edge, now tilted up and
worn by long erosion, forms First Mountain. Following this
eruption, deposition and depression continued as before through
a long period of quiet, during which the great lava sheet was
buried under about 600 feet of additional sediments.
Origin of the Double Flow of Second Mountain,
Again the trough-like belt of depression was fissured and an-
other flow of lava followed, forming a sheet of about 500 feet
in average thickness.
The beginning of the great Passaic Basin syncline of the
Watchung Mountain region probably dates from this period.
The first gentle sagging was chiefly confined to the southeastern
area of the, Watchungs, in the region northeastward from Bound
Brook. Consequently subsequent sediments were somewhat
concentrated in' this region tending to keep it graded up to the
level of the surrounding area; but sedimentation was locally ex-
ceeded by depression, and possibly a lake was formed here, until
the slow and gradual processes of deposition were again violently
interrupted by eruption. Upon the thin blanket of sediment,
I)erhaps less than 50 feet thick in the synclinal axis, and over the
adjoining bare areas of the preceding flow, another lava sheet
was spread with an average thickness of about 500 feet. Un-
like the preceding flows, this was not even approximately uni-
form in thickness. In the more depressed synclinal area the
ORIGIN NEWARK ROCKS. 125
maximum thickness was at least 800 feet, while on the flanking
bare areas of the preceding flow it did not exceed 200 feet. Thus
the great double sheet of trap, now tilted up and outcropping in
Second Mountain, is separated by a thin deposit of shale in the
synclinal axis ; hence the notable double crest around its curved
southwestern extremity.^
Continued gentle sagging of the newly formed Passaic Basin
syncline again caused increased thickness of the overwashed sedi-
ment in the central areas during the long period of quiet deposi-
tion that followed.
Origin of the Long Hill Bxtry^ive,
The great double sheet of Second Mountain was buried be-
neath 1,500 to 2,000 feet of mud, when occurred the fourth, and,
so far as the records preserved to us show, the last interruption
of quiet deposition by renewed igneous activity. This final out-
pouring was small as contrasted with the enormous flows that
preceded it. Its average thickness was probably not over 300
feet, and it apparently did not completely cover the area within
the present basin of the upper Passaic River. Its irregular
lobes may account for the present disconnected outcrops about
New Vernon, and in Long Hill, Riker Hill, Hook and Packanack
mountains. On the other hand, these may be the result of small
local lava flows through several independent vents.
Finally the red shales overlying this last trap sheet, and now
underlying the glacial drift and the recent river and meadow ac-
cumulations of the upper Passaic Basin, were gradually deposited
in.the uneventful period that followed the last volcanic outburst.
Origin of the Intrusive Trap Masses,
As to Kummel's conclusion that the great intrusive traps were
formed late- in Newark time there can be no question, since sev-
eral of the masses penetrate rocks that lie far above the middle of
* This double crest of Second Mountain has heretofore been explained upon
the hypothesis of a "curved longitudinal fault." A discussion of this
hypothesis will be found on page 112.
9 GEOL
126 THE STATE GEOLOGIST.
the series. He further states^ that "there are good reasons for
believing that many, probably all, of the intrusive sheets are
younger than the extrusive, although the evidence is not con-
clusive," and suggests that intrusive sheets may have been
formed only after the overlying sediments became so thick that
the lava could not readily rise to the surface. According to any
theory of deposition, however, the elevation of the surface did
not vary greatly during the whole of Newark time. The force
necessary to lift the lava to the surface would be little greater,
therefore, at the close of deposition than at the beginning. ,
It is quite probable, however, that many of the deeper-lying
strata had become appreciably consolidated by the close of the
I)eriod, and that the several extrusive lava sheets now included
in the series formed an additional barrier against further erup-
tion. But inherent in the nature of the rocks themselves there
was also a strong tendency to intrusion. The specific gravity
of the trap averages about 3.0, while that of the sediments is ap-
proximately 2.5. Thus for every hundred feet in height of a
column of lava there is an excess pressure of about 20 pounds per
square inch over that of the inclosing strata. In case of such
lava forced to the surface through 12,000 feet of sediments, the
difference in pressure is 2,400 pounds per square inch at the bot-
tom of the series. This is the measure of the tendency to intru-
sion. A standing column of such material, if it could be main-
tained in a liquid state would all find its way into the lower
strata, lifting the overlying beds upon its surface. A gentle
welling up of lava under such conditions, if it ever occurred,
would necessarily result chiefly in intrusive masses. The over-
flow, then, is roughly a measure of the force of eruption in px-
cess of that required merely to lift the lava to the surface.
Since cohesion in unmetamorphosed strata is always less along
the bedding-planes than across them, solidification, in whatever
degree, would also favor intrusion, unless the eruption followed
a previously formed fissure. In the latter case the reverse would
be true. The progressive consolidation of the sediments, there-
fore, and the resistance of the great lava sheets already imbedded
* Ann. Report of State Geologist of New Jersey 1897, p. 99.
ORIGIN NEWARK ROCKS. 127
in the upper strata would furnish predisposing conditions which
might divert an eruption of considerable violence into subter-
ranean channels. Hence it is altogether probable that the prin-
cipal intrusive bodies were formed after the surface flows, and
possibly in the early stages of those disturbances that put an end
to deposition and eventually led to the deformation of the whole
series by elevation, folding, and faulting.
DEFORMATION AND EROSION.
The folding and. faulting to which both the sedimentary and
igneous rocks have been subjected were occasioned to some ex-
tent by the subsidence of the Piedmont region during the accum-
ulation of the sediments, but much more by the uplift that re-
versed the direction of moveijient, raised the whole formation,
and gently tilted it to the northwest. In some places the strata
were wrinkled into low folds, and two great faults displaced
the central portions in the southwestern part of the New Jersey
. area. Other faults are found to determine the greater portion
of the northwestern boundary, and numerous smaller ones occur
throughout the region. The boundary faults belong to the pre-
ceding period of depression, and possibly some of the others also
date their beginnings from that i)eriod.
It is a point worthy of note that, almost without exception, the
known faults of the Newark strata in New Jersey have, the down-
ward displacement on the southeast side and the up-throw on the
northwest side of the fissure. Bearing in mind the further fact
that the sandstones and shales of this series usually dip north-
westward from 10 to 15 degrees in quite a regular monocline,
it is readily understood how the great Hopewell and Flemington
faults of the southwest (PI. XXVIII), involving displacements
of many thousands of feet, have caused a threefold repetition of
the stata and their included trap sheets along the Delaware River
above Trenton. Thus at least half of the great width of the
Newark belt in that region is due to this repetition of the series
by faulting.
No such great faults are known in the central and northeast-
em parts of the belt, but displacements of smaller amounts,
128 THE STATE GEOLOGIST.
ranging from less than a foot to several hundred feet, are fre-
quent in the trap sheets of the Palisades and the Watchung
Mountains ; and occasionally in fresh exposures of the rocks,
similar faults are observed in the sediments. The monotonous
uniformity of the shales and the sandstones, however, renders
the detection of such faults well nigh impossible under ordinary
conditions, apart from the trap sheets. Under the very prob-
able assumption that the intervening areas are as greatly affected
in proportion as the trap outrops, it will be seen that no incon-
siderable fraction of the width in the central and northeastern
portions of the Newark area is probably due to repetition on a
small scale by numerous faults.
These movements of faulting and folding, together with the
enormous erosion which the entire region has since undergone,
have been the determining causes of the present topography,
particularly the altitude and location of the trap ridges. The
causes of these movements have been fully discussed by previous
writers.^
The Supposed Fault Along the Hudson River.
It has been often supposed that the southeastern boundary of
the Newark along the Hudson River has been determined by a
fault, and that in a measure this fault has influenced the lower
course of the river. The existence of such a fault has not been
fully established, however, since very little is known of the
nature of the contact between the Newark strata and the crystal-
line foundation on which they rest. Several deep wells in Ho-
boken, Jersey City, and Bayonne^ that have penetrated from
I, GOG to 2,000 feet of sandstone very near the border seem to
lend support to the fault hypothesis ; but in all cases these may
also be explained as normal overlaps with the Newark strata
dipping 15 to 20 degrees to the west.
^Davis, 7th Ann. Rep. U. S. Geol. Survey, pp. 484-487- See also i8th Ann.
Rep. U. S. Gcol. Survey, p. 140; Ann. Rep. State Geologist of N. J. for 1897,,
p. 146.
'Ann Rep. State Geologist of N. J. 1882, p. 140; 1898, p. 139; 1904, pp.
264, 266.
ORIGIN NEWARK ROCKS. 129
Neither is it necessary to suppose an intervening fault in order
to explain the contraposition of the Palisades with their under-
lying shales and sandstones on one side of the river and the
prominent hills of crystalline rocks on the other. The projec-
tion of the lowest strata across the Hudson with a dip much less
than the average in this vicinity would carry them well over the
tops of the opposite hills. In fact the characters of both the
sediments and the trap of the Palisades make it quite certain that
these rocks once extended considerably further northeastward
than their present limits; and from, the theory of continental
origin of the sediments here advocated it is not at all improbable
that they were formerly continuous with those of the Southbury
and Connecticut Valley areas of Connecticut. Evidence of such
an extension for the Palisades trap sheet has been recently pre-
sented by Julien.^
Age of the Faults.
That the principal period of faulting was subsequent to the
formation of the intrusive trap masses, as well as the sediments
and the extrusives is evident from the following considerations :
(i) The numerous faults by which all these rocks are displaecd
throughout the area. (PI. XXVIII). (2) The shearing off of
one side of the Passaic Basin syncline, including the extrusive
trap sheets and the uppermost strata of the series, by one of the
great faults of the northwestern boundary, and the arms of the
intrusive trap of Cushetunk Mountain by another. (3) The
extrusive trap at Sand Brook is cut and the great intrusives of
Sourland Mountain, Mount Gilboa, and Byram are brought up
in a repeated sedimentary series by the Hopewell and Eleming-
ton faults. .(4) No intrusive trap in the Newark area has yet
been found to follow or to send off branches along any of these
fault fissures, and hence there is no evidence of igneous activity
either during or subsequent to these disturbances.
April 10, 1907.
* Science, New Series, vol. 25, 1907, p. 184.
The Newark (Triassic) Copper Ores
of New Jersey.
BY J. VOI.NEY I.EWIS.
CONTENTS.
Introduction.
Acknowledgments.
Copper-bearing minerals in the trap.
Copper ores in the sedimentary rocks.
The Griggstown (Rocky Hill) copper mine.
Location.
History.
Extent of workings.
Geology.
Character of the ores.
Occurrence of the ores.
Prospects.
The Arlington (Schuyler) copper mine.
Location and history.
Extent of workings.
Nature and occurrence of ores.
Prospects.
The Flemington copper mine.
Location and histdry.
Extent of workings.
Character and occurrence of ores.
Prospects.
The Somerville copper mine.
Location and history.
Extent of workings.
Equipment.
Character of the ore.
Occurrence of the ore.
Prospects.
Old mines at Chimney Rock and Plainfield.
Mines near Chimney Rock.
Mines near Plainfield.
Prospects.
(131)
132 THE STATE GEOLOGIST.
Copper deposits back of First Mountain.
The Hoffman mine.
Pluckamin to Feltville.
The New Brunswick copper mines.
The New Brunswick or French mine.
The Raritan mine.
The Menlo Park copper mine.
Location and history.
Geologic conditions.
Character and occurrence of the ores.
Prospects.
Copper ores in other localities.
Copper ores .at Glen Ridge.
Copper and silver at Newtown.
Copper ores at Fort Lee.
On Pennington Mountain.
Origin of the Newark (Triassic) copper ores.
Weed's hypothesis.
Objections to Weed's hypothesis.
A hydrothermal hypothesis.
Origin of ores with intrusive traps.
Origin of ores without associated intrusives.
Summary of origin.
Age of copper ores.
INTRODUCTION.
Since early in the eighteenth century the copper deposits of
New Jersey have attracted more or less attention, and have been
the objects of rep^eated attempts to mine and smelt them. In
the early days some of these efforts were quite successful for
the times ; but for half a century, at least, they have uniformly
led to disappointment and failure, and since the development of
the great native copper deposits of Lake Superior and the ex-
tensive ore deposits of the west and southwest they have almost
dropped out of mind. From time to time, however, one locality
or another has been taken up, some of the old workings reopened
and perhaps a little additional work done, only to be abandoned
again after a few months or a few years. Such, in brief, has
been the history of the New Jersey copper industry for nearly
two centuries. Since the establishment of the State Geological
Survey the various reports have recorded the rise and fall of
these i)eriodical waves of interest.
TRIASSIC COPPER ORES. 133
The fact is that, with one or two exceptions, little or nothing
is positively known of the degree of success attained in the early
operations, except that for one reason or another they were not
permanently successful. It is known, however, that it was often
difficult, and even impossible, to drain the workings except to
very shallow depths; that concentration, beyond hand cobbing,
was in most cases crude and inefficient; and that, in the later
times, efforts have often been ill-directed and money wasted for
useless appliances.
It may reasonably be questioned whether, in any case, the
average grade of available ore has been satisfactorily established,
and it is quite certain that nowhere has the existence of any
great body of ore yet been demonstrated. This is the more to
be regretted because in some instances considerable deposits may
reasonably be expected, and, with proper direction, the money
already expended upon them would have determined the matter
long ago. In the following report, however, all available in-
formation is given concerning every deposit of past or present
importance, together with such conclusions as may safely be
drawn from present knowledge, and, in a few cases, suggestions
as to future operations.
Whether or not any of these mines shall ever again prove
commercially profitable, they constitute an exceedingly interest-
ing example of a class of ore-deposits, and are ot considerable
importance in investigating the principles of their origin. It is
hoped that the discussion under this head may contribute some-
thing toward the advancement of this branch of applied geology.
This will have been accomplished, in a measure at least, if these
observations serve to direct the attention of geologists to these
deposits and to stimulate discussion.
ACKNOWI.EDGMENTS.
The author is especially indebted to Mr. W. S. Valiant, assist-
ant in the Geological Museum of Rutgers College, for careful
and thorough determination and verification of the minerals en-
countered in the ores and trap rocks in this study. Thanks are
134 THE STATE GEOLOGIST.
also due to the officers and owners of the mines near Rocky Hill,
Arlington, and Somerville for courtesies extended in the exami-
nation of the properties, and to Mr. Thomas A. Edison for in-
formation in regard to the old workings near Menlo Park. Re-
ports and published articles referred to in the text are duly-
acknowledged in footnotes.
COPPER-BEARING MINERAI.S IN THE TRAP.
Visible grains of chakopyrite (the brassy-yellow copper-iron
sulphide) are not infrequently found in the trap rocks, particu-
larly in the intrusives, where the constituent minerals are de-
veloped in larger grains and hence are more distinct. The same
mineral also occurs commonly with the abundant calcite and
zeolites resulting from the alteration of the more vesicular and
cavernous portions of the extrusive traps, and in veins of similar
secondary minerals generally. Flakes and thin sheets of metallic
copper are also found in veins and joint-cracks, and more rarely
rounded shot-like and irregular granules of copper occur in the
more massive portions of the trap of First Mountain. Such
occurrences are frequently encountered in the American Copper
Company's mine north of Somerville and in the quarries at Chim-
ney Rock, north of Bound Brook. At the latter locality metallic
copper is sometimes found in the trap as much as 40 or 50
feet from the base of the sheet.
Copper is also known to occur as a constituent of the pyroxenes^
the principal dark-colored mineral of the trap rocks. Weed^ cites
200 assays of the trap of First Mountain, made for Josiah Bond,
which yielded an average of one-fortieth of one per cent, of
copper. The fresh central portions of trap prisms were also
crushed and the heavy minerals concentrated by "horning."
These, upon examination by Hillebrand, in the laboratory of
the United States Geological Survey, showed an appreciable
amount of copper.
For the purposes of this investigation, typical specimens of
the coarse-grained intrusive trap from the quarry at Rocky Hill
*Ann. Rep. of State Geologist for 1902, p. 136.
TRIASSIC COPPER ORES. 135
were crushed, and separated by heavy solution in the laboratory
of the Geological Survey. The pyroxene thus obtained was
tested for copper by Mr. R. B. Gage, and yielded 0.019 per cent.,
nearly one-fiftieth of one per cent.
Along oxidized and stained joint-cracks of the various trap
masses chrysocolla (the bluish-green copper silicate), a little
malachite (the green carbonate) and, more rarely, azurite (the
blue carbonate), not infrequently occur. These are manifestly
the results of alteration of some of the copper-bearing con-
stituents of the trap described above, by means of the percolating
surface waters that have partially altered the trap itself.
COPPER ORES IN THE SEDIMENTARY ROCKS.
The only ores of copper that have thus far attracted attention
in the Newark rocks of New Jersey as of possible commercial
value occur in the shales and sandstones. (See PI. XXX.) They
consist of disseminated grains and irregular masses, with occa-
sional vein-like aggr^fates and impregnated fault-breccias.
Seventy years ago Professor Rogers concluded "that the ore does
not exist in any instance in the shape of a true vein," but that
it "has been injected into the body of the red shale and sand-
stone" of the regular stratified series.^
The principal copper-bearing minerals are chalcocite (copper
glance, the black copper sulphide), and native copper. Asso-
ciated with these are varying amounts of secondary copper
minerals that have resulted from alteration by surface waters.
The chief of these is chrysocolla^ (the bluish-green copper sili-
* Report of the Geol. Survey of N. J., Henry D. Rogers, Philadelphia,
1836, pp. 167, 169.
* Without exception the available literature of the Newark copper deposits
places the emphasis on malachite as the important secondary ore, whereas
the present studies of the copper minerals, both in the mines and in the col-
lections at Rutgers College, -show a great preponderance of chrysocolla in
every instance. More or less green carbonate is usually present (rarely
azurite), but the silicate occurs in great abundance. This curious predilec-
tion for malachite is doubtless the result of unverified tradition accepted
without question by each succeeding generation, since the error was not
sufficiently evident to be detected on casual inspection.
136 THE STATE GEOLOGIST.
cate), and there are smaller quantities of cuprite (the red copper
oxide), malachite (the green copper carbonate) and azurite (the
blue copper carbonate) .
The modes of occurrence and associations of these ores are
quite varied, as regards both the sedimentary and the igneous
rocks. They may be classified, however, under four distinct
types, two with and two without accompanying intrusive traps,
as follows:
I. With intrusive trap rocks.
1. In the zone of metamorphic, or "baked," sedimentary rocks
accompanying the intrusive traps, as at the Griggstown (Rocky
Hill) mine.
2. In unaltered sandstones and shales intersected by small trap
dikes, as in the Arlington and Flemington mines.
II. Without associated intrusives.
1. In unaltered (or but slightly altered) strata associated
with extrusive trap sheets, as at numerous localities along First
Mountain, near Pluckamin, Somerville, Bound Brook and Plain-
field.
2. In unaltered strata entirely apart from known trap masses
of any kind, as at New Brunswick, Glen Ridge and Newtown.
THE GRIGGSTOWN (rOCKY HII.I.) COPPER MINE.
Location, — ^This mine, the property of the New Jersey Copper
Cb-mpany, is located i mile south of Griggstown, 2 miles north-
east of Rocky Hill, the nearest railway station, and J4 a mile
east of the Millstone River and the Delaware and Raritan Canal.
It has also been called the Franklin mine.
History, — As early as 1753 a newspaper reported that "a valu-
able Copper Vein of Six Foot Square is very lately found there, "^
and various shares in the mine were offered for sale about 12
years later. It is said that 160 Welsh miners were employed in
the mine at one time before the Revolutionary War, and that
considerable ore was concentrated and shipped to England. It
^ Pennsylvania Gazette, Jan. 16, 1753, reprinted in New Jersey Archives,
vol XIX, p. 234.
TRIASSIC COPPER ORES.
137
was again operated early in the nineteenth century and several
later attempts have been made to work the mine by reopening
portions of the old workings. In 1906 the deepest shaft was
cleared to the bottom, probably for the first time in over a cen-
tury.
Extent of workings, — ^The principal shaft is 190 feet deep
(Fi?- 5)' "^^^ workings of the first level, about 100 feet deep,
COPPER MINE
HIM ROCKY HILL
SOMfRSET COUNTir, H,J.
^MUi *t IM> rt UVCL
Pig' 5.
Map and section of the old workings at the Rocky Hill Mine (Griggstown)
also communicate with the surface by an inclined shaft and by
a drainage tunnel 1080 feet long. There are several other
shafts now caved in, and some stoped-out chambers of con-
siderable size, as shown in figure 5.
Geology, — ^The crest of the ridge rising east of the mine is
the outcrop of coarse-grained intrusive trap rock, which con-
tinues southwestward and connects with the larger sill of similar
138 THE STATE GEOLOGIST.
rock that forms the crest of Tenmile Hill and Rocky Hill. This
northeastward offshoot of the trap has been intruded conformably
between the strata of the shales, which strike N. 45° E. at the
mine and dip from 10° to 20° N.W. Throughout the length of
this ridge and westward along Rocky Hill, the shales overlying
the trap have been greatly altered by the heat of the intrusive
mass. This is most noticeable in the change of color which they
have undergone. On the lower slopes of the ridge, below the
mine, the normal dark-red color appears. Further up the slopes
this gradually changes, through various shades of purple to the
dark-gray, brown and almost black homstone that is found in
the mine. It is often thickly spotted with rounded and rectangu-
lar masses of chlorite (probably an alteration product of cor-
dierite), ranging in size from minute specks to an inch in diameter.
Offshoots of the underlying trap sill form several dikes through
the shales. One of these about 60 feet thick was cut in the work-
ings just west of the shaft, and several oval and irregular out-
crops appear in the vicinity to the west and north of the mine.
It is clear also that the trap cannot lie far below the present
workings, if it continues approximately conformable to the strata,
and any great extension in the depth of the mine would have to
be made to the northwest.
Character of the ores, — The essential ore at this mine is
chalcocite, or glance (the black copper sulphide), with occasion-
ally a little chalcopyrite (the brassy-yellow copper sulphide), and
small quantities of secondary chrysocolla (the bluish-green cop-
per silicate), malachite (the green copper carbonate), and cuprite
(the red copper oxide). Associated with the ore-minerals are
frequently found tourmaline, magnetite, hematite, epidote, and
occasional feldspar crystals, besides the abundant nodules of
chlorite, described above.
Native copper, tenorite and bornite have been reported from
this mine,^ but a careful search of the mine, the old dumps, and
old collections from this locality in the Geological Mluseum of
Rutgers College failed to verify any of these. A small quantity
of native copper is, however, to be expected, and the chalcocite
' Weed, Bull. U. S. Geol. Survey, No. 225, p. 188.
TRIASSIC COPPER ORES. 139
is frequently so intimately mingled with magnetite and hematite,
as shown by microscopic sections of the ore, as to be readily
mistaken for bornite with the ordinary blowpipe reactions. Some
of the soft black masses of magnetite, hematite, or tourmahne
also present physical characters much like tenorite.
Occurrence of the ores. — Chalcocite is the original ore. It
occurs in fissures an^ brecciated zones in the hard, .flinty horn-
stone, which is sometimes bleached to a light gray or white in
the vicinity of the ore. The chalcocite also penetrates minute
cracks in the homstone, and occurs as a constituent of some of
the chlorite nodules with which the stone is often thickly studded.
One of the bedding-planes of the hornstone carries fronf 3 to 12
inches or more of soft, clay-like material charged with ore. This
material bears evidence of slipping, and seems to have been de-
veloped along a thrustplane following the stratification. It
seems to have furnished most of the ore in the earlier workings.
The secondary ores, chrysocolla, cuprite, and malachite, formed
from the later alteration of chalcocite and chalcopyrite by per-
colating surface waters, occur with the primary ores in the fis-
sures and brecciated zones. They also penetrate the adjoining
strata along joints and bedding planes to a considerable distance,
and large masses of the rock are sometimes impregnated with
, the green stains of chrysocolla. Cuprite and malachite are far
less abundant.
Prospects. — So far as accessible the old workings do not show
any considerable amount of workable ore. All such bodies as
were encountered seem to have been pretty thoroughly stoped
out. The conditions under which the ores were found seem to
be of greater extent than the old workings, however, both laterally
and in depth, so far as may be judged from those at present
known. Since the mine has been reopened probably to the greatest
depth attained here, it is worth while to determine whether or
not this is true, and if so to extend the drifts beyond the limits
of the old workings in prospecting for further bodies of work-
able ore.
140 THE STATE GEOLOGIST.
THE ARLINGTON (SCHUYLEr) COPPER MINE.
Location and history. — This mine is located in North Arling-
ton, Hudson County, about a mile northeast of Arlington station
Fig. 6.
Map of Arlington, showing trap rocks, fault and old copper \
(Schuyler Mine), after Darton.
Pig- 7-
Cross section at A, figure 6, Arlington (after Darton).
on the N. Y. & Greenwood Lake Railroad, and about 8 miles
from New York City. (Fig. 6.) It is the oldest mine in the
State and was probably the first cc^per mine operated in America.
TRIASSIC COPPER ORES. 141
It was discovered early in the eighteenth century, probably about
1 7 19, and a shipment of no casks of ore from New York in
1 72 1 was probably the first exported from this mine. In spite
of serious trouble with water in the lower levels, the mine was
extensively worked in Colonial times and was a source of con-
siderable wealth, for the times, to its owners, the Schuyler family.
Since the Revolution the mine has been repeatedly reopened and
operated for longer or shorter periods, and at one time (1859-
1865) it is said that 200 laborers were employed in the mine and
mills. An expensive mill and reduction plant designed to treat
125 tons a day were erected at the mine in 1900, but short ex-
perimental runs proved that it was not adapted to the ore, and
the mine has now lain idle for several years.
Extent of workings. — "The Victoria shaft is reported to be
347 feet deep, but all is mud below the 240-foot level and diffi-
cult of access. (Fig. 8.) The old Cornish pump is still in posi-
tion in the bottom of the shaft, buried in mud and fallen timbers.
It is said that there are three drifts from the bottom of the shaft,
one toward the northwest about 180 feet long, one running south-
west 180 feet long, and the third running north about 210 feet.
The mill at this time was near the mine and had 25 stamps of
the old Cornish type with wooden stems. The ore as it came
from the mine was cobbed and handpicked. The high-grade
material was shipped without further treatment, and the lower
grade was concentrated by jigs and buddies." ^ In all 42 shafts
are said to have been sunk on the property, but only one, the Vic-
toria, has been kept open. There are also 3 drain tunnels, one of
which drains the mine to the lOO-foot level. Two inclines have
been run in from the face of the bluff overlooking the Newark
Meadows. One of these is 220 feet long and the other 80 feet.^
Figure 8 shows the workings above the 240-foot level.
Nature and occurrence of ores, — The ore at Arlington is chaU
cocite, or copper glance (the black copper sulphide) with much
^ J. H. Cranberry, Engineering & Mining Jour., vol. LXXXII, 1906, p. 11 18.
'Annual Report of State Geologist for 1902, p. 129. The number of shafts
Jhas also been given as 32, and other details of the old workings vary some-
what in the different descriptions. See Engineering & Mining Journal, Vol.
69, 1900, p. 135, and Vol. 82, 1906, p. 11 16.
10 GEOL
142
THE STATE GEOLOGIST.
secondary chrysocolla (the bluish-green copper silicate), and
smaller amounts of malachite (the green copper carbonate). A
little azurite (the blue copper carbonate), cuprite (the red copper
oxide), and occasional particles of native copper are also found.
The ore occurs in unaltered gray arkosic sandstone, which is
Fig. 8.
Map and section of the old workings at the Schuyler Copper Mine.
Engineering and Mining Journal, vol. 69, p. 135.)
(After
penetrated by small irregular branching trap dikes and over-
lain by red shale. The chalcocite is found chiefly in branching
veins and seams in the sandstone near the small dikes and in the
frequent fault breccias of sandstone and trap. (Compare fig. 7.)
The larger pockets of the ore sometimes exhibit cleavage faces
TRIASSIC COPPER ORES. 143
an inch in width. These masses are sometimes thickly filled with
quartz grains or with minute reddish crystals of feldspar. The
sandstone is irregularly stained with the green chrysocoUa and
also contains occasional scattering grains of chalcocite. This im-
pregnated sandstone occurs in two layers, the upper about 12 feet
thick and the lower about 10 feet, separated by one foot of shale,
these have a westerly dip of about 9 degrees. The workings have
been chiefly confined to the upper sandstone.
"Over wide areas in this mine the surface of this sheet [of in-
trusive trap] is smooth and conformable to the gently dipping
sandstones, but there are irregularities in which the strata are
crossed for a few feet, and the sheet also sends several offshoots
up into the sandstone. It is stated that the diabase surface was
followed westward for a half a mile in the mining operations,
and that at one point it is traversed by a fault of considerable
amount." ^
Prospects. — Systematic sampling by a competent mining en-
gineer in 1900 is said to have given an average of slightly more
than 2 per cent, of copper for the upper sandstone, as exposed in
the present workings, and a little less than that amount for the
lower sandstone. A small amount of silver is always present, but
probably not enough to repay cost of recovery. ^ If an average of
2 per cent, copper content can be established over any large part of
the property, the question of successful mining would seem to re-
solve itself into the questions of economic reduction and compe-
tent management. The sandstone can be mined and crushed very
cheaply on a large scale, and rich seams and pockets of glance in
the fault breccias and along the courses of the thin trap dikes
might be expected to add appreciably to the output of the mine
in the future, as they have done in the past. At any rate the mine
is worthy of conservative investigation, in spite of past failures,
by extending the drifts so as to block out systematically a large
' N. H. Darton, U. S. Geol. Survey, Folio No. 83, p. 10.
* It is of interest in this connection to note that a blowpipe assay of a rich
specimen of ore from this mine, made in the Mineralogical Laboratory of
Rutgers College by Mr. Harry R. Lee, yielded 4.4 oz. of silver per ton and a
gold bead that was distinctly visible.
144 THE STATE GEOLOGIST.
body of ore, or by thorough exploration with a core-drill. If a
large body of workable ore can be thus established, the most
economical method of treatment should be very carefully deter-
mined and the plant so modified as to adapt it to the character of
the ore.
THE FI.EMINGTON COPPER MINE.
Location and history, — The mine is located half a mile south-
west of the court house in the town of Flemington, Hunterdon
County. The ore was evidently discovered prior to 1834, since
it is referred to in a publication of that date as having been
"lately discovered, but not yet extensively explored.''^ It has
been said that work was also done here "in the early days," but
there seems to be no record of this. Active operations were under
way, however, at the time of Professor Rogers visit in. 1835,^
and it is said that $400,000 were expended in opening and equip-
ping the mine. Afterwards various attempts to operate it were
made by several companies, and much prospecting was done in
the effort to establish min/&s in the region from Flemington to
Copper (Hill, 2 miles to the south. All of these undertakings
were soon abandoned, however, and no active operations have
been attempted since 1860.^
Extent of workings. — The workings were located immediately
beside a brook, and pumping must have been necessary from the
beginning. A mill and a smelter were erected, of perhaps 25
tons capacity, judging from the dilapidated portions of the plant
still standing, and considerable active work was done, as attested
by the large dump-heaps about the old shafts. Several shafts
were opened, but their depth and the extent of other underground
workings have not been learned.
Character and occurrence of ores. — The ore was found in partly
altered brownish-red and purplish shales in the vicinity of trap
dikes. It consisted essentially of chalcocite (the black copper sul-
*A Gazetteer of the State of New Jersey, by Thos. F. Gordon, Trenton,
1834.
* Rept. Geol. Sur. of N. J., by Henry D. Rogers, Philadelphia, 1836, p. 167.
* History of Hunterdon and Somerset Counties, New Jersey, by Jas. P.
Snell, Philadelphia, i88i.
TRIASSIC COPPER ORES. 145
phide), cuprite (the red copper oxide), chrysocolla (the bluish-
green copper silicate), and malachite (the green copper car-
bonate), associated with calcite. Chcdcopyrite (the brass-yellow
iron-copper sulphide) is often disseminated in grains through the
larger masses of chalcocite. A series of trap dikes cuts the shales
and sandstones northward from the great intrusive sill of Sour-
land Mountain to Flemington. It is in the sediments accompany-
ing these dikes that the copper ores of the region from Copper
Hill to Flemington occur.
Professor Rogers^ described the conditions in a series of east
and west cuttings that were^being made across the ore-body at
the time of his visit. "A belt of metalliferous rock" was un-
covered "of very variable width, sometimes as wide as 20 or 30
feet, which preserves nearly a north and south direction for
several hundred feet," with strong indications of a precisely
similar ore 2 miles to the south. The ore is described as "in-
timately blended or incorporated with the semi-indurated and
altered sandstone, and the mass has therefore somewhat the aspect
in certain portions of a conglomerate of recemented fragments,
the metalliferous part being the cement. Most commonly the
ore is thus minutely disseminated, though now and then it occurs
in lumps of great purity and considerable size."
Prospects, — ^The geological conditions are seen to be closely
similar in many respects to those of the Schuyler mine at Arling-
ton, but much less is known of the value and extent of the ore
bodies encountered. In the absence of such information, nothing
can be said that might in any way offset the discouraging experi-
ence of those who have attempted at various times to operate the
mine.
THE SOMERVIIvLE COPPER MINE.
Location and history, — ^This is the old Bridgewater mine,
located 3 miles north of Somerville, Somerset County, on the
* Rept. Geol. Sur. of N. J., by H. D. Rogers, Philadelphia, 1836, p. 169.
146 THE STATE GEOLOGIST.
southwestern slopes of First Mountain. The ore was known
here and some of the old drifts in the vicinity were run before
the Revolutionary war. Active work was again begun in 1821
and continued more or less intermittently at many points from
this mine southeastward to Chimney Rock, a distance of 4
miles, during the next two decades. In the meantime a smelter
was erected at Chimney Rock and another near the Bridgewater
mine. Some mining was also done east of Chimney Rock in
1866. No further work was done until 1881, when explorations
were again begun at the Somerville mine, and drifts were run
into the mountain side along the 'contact of the trap and the
underlying shales. Similar exploratory work has been done at
intervals since, especially in the extension of the work along the
under contact of the trap.
Extent of workings. — The principal opening is a sloping
tunnel, or incline, following the contact of the shales with the
overlying trap, as explained above. This contact plane dips
slightly more than 10 degrees toward the northeast, and the
tunnel has been driven into the mountain 1,240 feet. Drifts of
varying length have been opened on alternate sides of the incline
at intervals of 30 feet, and in a few instances considerable
chambers have been excavated. The aggregate length of incline
is 1,400 feet, and of side drifts 2,040 feet. A drainage tunnel
catches the surface waters that find their way into the mine and
also drains the upper workings. The water ifrom the lower
portions is also pumped into this tunnel
The old dumps along the mountain slopes toward the southeast
show that many tunnels of considerable length have been run
between the mine and Chimney Rock. On the east side of the
gorge at Chimney Rock, also, a tunnel 300 ifeet long runs into
the mountain to the contact of the trap and branches each way
along this contact for 100 feet, while another tunnel was driven
only 20 feet below it.^
Equipment, — ^The mining plant consists of an 80-horse power
boiler, a 5-drill Rand compressor, running drills and pumps, and
a hoist with a 12-horse power Lidgerwood engine. The 50-ton
* Cook, Geology of New Jersey, 1868, p. 677.
TRIASSIC COPPER ORES. 147
mill is equipped with 60-horse power boiler and engine, crusher,
two sets of roughing rolls, drying screens, sizer, and two Wilfley
tables.^
Character of the ore. — ^The ore of the Somerville mine is essen-
tially native copper, altered above the depth of 100 feet (600 feet
on the slope) to cuprite (red copper oxide), chrysocolla (green
copper silicate), and malachite (the green copper carbonate).
Small grains and crystals of chalcocite (black copper sulphide)
and occasional particles of chalcopyrite (the brass-yellow iron-
copper sulphide) also occur, besides small amounts of hydro-
cuprite (orange-colored hydrous copper oxide). The copper
is silver-bearing and now and then small masses of native silver
are found.
Occurrence of tlie ore, — The ore occurs chiefly in the upper
two and a half feet of shales (varying from i to 3 feet)
immediately underlying the extrusive trap sheet, and penetrating
the trap itself usually to a distance of about 6 inches from the
contact with the shales. Locally the copper is found to extend to
much greater distances in both the shales and the trap. In
driving the drainage tunnel in the underlying shales, metallic
copper was found in nodules 8 feet below the trap, and a sheet
of cuprite coated with malachite was encountered 15 feet below
the contact.^ In the trap quarries at Chimney Rock, on the
other hand, numerous nodules flakes and sheets of copper have
been found in the trap as much as 40 or 50 feet above the base of
the sheet.
In the shales the copper occurs in minute grains and strings
and in nodules, sheets, and ragged masses of great variety of
form and size. Many years ago a mass plowed up in a field
on the mountain slope near the mine is said to have weighed
128 pounds. A portion of it now in the Geological Museum
of Rutgers College weighs 74 pounds, including perhaps a pound
of attached and included shale. The shale containing the copper
is bleached to various shades of reddish brown, gray and almost
white. Immediately about even the smallest grains, and to a
* Ann. Rep. State Geologist for 1902, p. 129.
•Ann Report of State Geologist of N. J. for 1903, p. 109.
148 THE STATE GEOLOGIST.
varying distance (a fraction of an inch to one or two inches)
from them, the inclosing shale is invariably of much lighter color
than the prevailing brownish red of other portions of the same
stratum and of adjacent regions. These bleached spots and mot-
tlings, while fairly well defined, are not separated by a sharp
boundary from the surrounding red shale. There is generally a
distinct transition zone of intermediate shades from an eighth
to a quarter of an inch or more in width. Also the thin lamina-
tion, which is distinct in normal portions of the rock, often dis-
appears altogether in the bleached spots about the copper.
The red shales of this and adjoining regions to the south, east
and west are frequently interspersed with thin tabular crystals
and clusters of calcite, which range in size from almost invisible
to more than an inch in diameter. (PL XXXI, A.) They are
apparently low flat rhombohedra. Often near the surface and
usually in the mine this calcite has been partly or wholly re-
moved by solution. In adjacent regions the cavities are often
lined with microscopic quartz crystals, and sometimes divided
by thin partitions of quartz, presumably deposited along cleav-
age planes of the calcite. In the mine, where the cavities are all
quite small, slit-like openings, they are often partly occupied by
little masses of copper and crystals of chalcocite; and this is
equally true of both the bleached and unbleached portions of the
shale. (PI. XXXI, B.) It would seem, therefore, that these
belong to a different period of formation from that of the prin-
cipal mass of the ore, which was deposited only in the bleached
areas of the shale. Occasional crystals of prehnite and chal-
copyrite also occur in these minute cavities near the trap.
In the upper 600 feet of the slope most of the copper has
been oxidized to cuprite, chrysocolla and malachite, which re-
place the disseminated particles, sheets and masses of the metal.
The base of the trap sheet is often vesicular and the cavities have
been filled with quartz, manganocalcite and zeolites, with fre-
quent lumps and stringers of copper. A northeast-southwest
fault encountered in the workings has displaced the strata about 4
feet, and has crushed and sheared the rocks considerably in places.
Prospects, — ^The mine requires no timbering, the overlying
sheet of solid trap forming a perfect roof. ' The ore is easily
Geological Survey, 1906.
Fig. A. Red shale with desseminated lenticular calcite. New Brunswick.
pij ^rrr] ^Tg '' F pw^''i^J "^T"Uiil | •]jpri'|^jr"P7"l'ff"" TJPiifl' ';!31T|''TJ',iTi'|i|i|'HJit!I|
TRIASSIC COPPER ORES, 149
mined and crushed, the inclosing rock being softer than the some-
what similar ores of the Lake Superior region. There is no
reason to doubt that the character of the ore will continue native
copper in depth, as in the last 600 feet of the slope, which has
evidently passed below the zone of oxidation. Repeated sam-
plings in recent years are said to have yielded an average copper
content of over 2 per cent, in the present workings. If a great
body of ore of this grade can be fully established there seems to
be no good reason why it should not be mined .at a profit, if
operated on a large scale. With the great advantages of its
location as to labor and fuel supply and its accessibility to the
markets of the East, its possibilities as a low-grade copper mine
•are worthy of investigation, and explorations should be suffi-
ciently extended to determine definitely the question of available
ore-supply for a considerable working period. Incidentally the
character as well as the quality and quantity of the ore would
thus be tested, and the type of mill required for its economical
treatment could be fully determined experimentally. No exten-
sive plant should be erected until this is done.
OLD MINES AT CHIMNEY ROCK AND PI^AINFlElvD.
Mine^ near Chimney Rock, — Similar conditions to those de-
scribed, which prevail along First Mountain for 4 miles south-
eastward, led to considerable work in the early days as far as
Chimney Rock and beyond. On both sides of the gorge of Middle
Brook at Chimney Rock numerous old workings are found, and
many of the drifts were several hundred feet in extent. One
on the east side of the brook is said to Have been driven in 300
feet to the trap and 100 feet each way along the contact. On
the. west side one of the old tunnels is said to have penetrated
700 feet. One of the old smelters, built early in the last century,
was also located here. A drift now open beneath the trap quarry
at Chimney Rock shows conditions almost identical with those
described above, although the shales are somewhat less bleached
about the disseminated ores than at the Somerville mine. Occa-
sional pieces of native silver are also found associated with the
ISO THE STATE GEOLOGIST.
copper at this locality. As noted above, grains and strings of
copper are now found here in the trap quarries as much as 40 or
50 feet above the base of the sheet.
Mines near Plainfield, — Northwest of Plainfield, in the gorge
of Stony Brook through First Mbuntain, extensive explorations
were made for copper early in the last century, and active mining
was going on- there at the time of Dr. Cook's visit in 1866, the
ores being sent to Bergen Point. Work was being done by two
companies at that time, and tunnels and drifts of several hundred
feet had been opened on both sides of the gorge, the longest
tunnel in each case being given as 400 feet.
The workings being in the oxidized zone the ores were the
same as in the upper workings at the Somerville mine, impreg-
nating the shale for a thickness of from 8 inches to 2 J^ feet from
the trap. The shales here dip 10 to 20 degrees a little west of
north. No ore was found in the base of the trap itself. Small
faults of 3 or 4 feet throw were encountered in places.^
Prospects. — Practically nothing definite is known of the grade
or extent of ore encountered in these old workings. As small un-
dertakings, under the adverse conditions of earlier times, they
were not successful, presumably for the reason that the amount of
rich ore encountered was very small. If, however, future explora-
tions should establish the existence of large bodies of workable
low-grade ore at one point along the base of First Mountain,
there would be every reason for the careful investigation of other
points where similar deposits are known to exist.
COPPER DEPOSITS BACK OF EIRST MOUNTAIN.
The Hoffman mine. — Two miles northwest of the Somerville
mine and three- fourths of a mile southeast of Pluckamin is the
old Hoffman mine, which has been worked at various times and
was said to have produced some ore for shipment. The shaft,
136 feet deep, penetrates the shales and sandstones and the under-
lying trap. The ore is said to be 4 feet thick and to carry
* Cook, Geology of New Jersey, 1868, pp. (176, 677.
TRIASSIC COPPER ORES. 151
some native copper. Materials collected from the old dump
•
show chalcocite in sandstone and in brecciated trap, with smaller
quantities of green carbonate (malachite). The breccia seems to
indicate that the ore occurs in connection with a zone of faulting.
Pluckamifii to Feltville. — From this point around the inner or
back slope of First Mountain for a distance of 17 miles, copper
minerals have been found at several places between the vesicular
upper portions of the trap and the overlying sandstones and
shales. Discovery of these minerals has led to prospecting in
the vicinity of Martinsville, Warfenville, Washingtonville, and
Feltville. The work at all these places was done many years ago,
however, and the conditions encountered are not known. At
Feltville the ore was said to be sulphide, probably the black sul-
phide, or glance, as at the Hoffman mine. It was associated
with pyrite in a thin rock-seam between the trap and the shales.
The contact as now exposed along the narrow ravine and in
some of the old pits and drifts shows no copper minerals.
THE NEW BRUNSWICK COPPER MINES.
The Nem Brtmswick or French mine. — ^About 1748 to 1750
*
many lumps of native copper weighing from 5 to 30 pounds
each, "upwards of 200 pounds" in all, were plowed up in the
field of Philip French, now Neilson Campus of Rutgers College,
at New Bnmswick. A company was formed to mine for copper
in 1750 and work was begtin by sinking a shaft the following
year. Grains of the metal were found in the red shales and sheets
in the joint-planes of the rock. Some of the latter of the "thick-
ness of two pennies and three feet square" are said to have been
found within 4 feet of the surface.
A depth of 60 feet or more was attained and some of the work-
ings are said to have extended several hundred feet under the
Raritan River, although there was much difficulty in handling the
water. A stamp-mill was erected and many tons are said to have
been shipped to England.^ Similar sheets of metallic 'copper
* Morse's Gazetteer; Morse's "American Universal History," 1805; Barber
and Howe's "Historical Collections of the State of N. J., New York, 1844."
152 * THE STATE GEOLOGIST.
from one-sixteenth to one-eighth of an inch in thickness and
one or two feet across have been found in grading the street
east of the campus of Rutgers College, and also in digging a
cellar on Somerset street on the southwest side of the campus.
The latter place has been recently partly exposed again, and the
copper is found in a zone of bleached grayish shale and in spots
of gray mottled with the normal red color along an east-west
fissure. The conditions. are an exact duplicate of those found
at Menlo' Park, described below, except in the direction of the
fissure, which is at right angles. Cuprite (the red oxide) and
malachite (the green carbonate), with occasionally a little chry-
scfcolla (the silicate) and azurite (the blue carbonate), are some-
times found incrusting such metallic sheets or entirely replacing
them in the joint cracks of the shales. There is no evidence or
indication that trap rock was ever encountered in these old work-
ings at New Brunswick. The well back of the Rutgers College
gymnasium, 244 feet deep, and one at Johnson & Johnson's fac-
tory, 480 feet deep, are both in the immediate vicinity of the old
copper mine, while th*e one on Bishop Place, 455 feet deep, is
little more than a block to the north of it. In all of these the
usual red shales of the region were penetrated, with occasional
purplish and sandy layers. The purple shales, which are also
occasionally seen at the surface in this vicinity, may indicate the
presence of intrusive trap at no great depth.
The Raritan mine. — About 3 miles southwest of New
Brunswick is the old Raritan mine. "The main shaft was 160
feet deep, from which a timnel was driven in a north-northeast
direction. Another shaft northeast of this one did not reach the
ore. All of them are now filled with water. The rock of these
shafts lying at the mouth of the mine is mostly red and bluish
shales. Very little trap was seen in these rubbish heaps. The
ore is mostly a carbonate with some sulphide. The difficulty in
working this mine was the trouble with water."^ The workings
were not far from some small dikes that are known to intrude
the shales in that vicinity, and may possibly have encountered
some di these. Otherwise the conditions are apparently the same
as at New Brunswick.
* Cook, Geology of New Jersey, 1868, p. 679.
TRIASSIC COPPER ORES. 153
THE MENLO PARK COPPER MINE.
Location and history, — The old workings are half a mile north
of Menlo Park and 7 miles northeast of New Brunswick. Copper
was discovered here, it is said, about 1784,^ and the workings
were so old in 1820 that "no vestiges of copper remain upon the
surface/'^ Attempts were made to work the mine before the war
of 181 2, again in 1827, and in the eighties of the last century.
Later spasmodic efforts have been made from time to time, and a
stock company, organized early in the present century, installed
hoisting and pumping machinery, a tube mill, and jigs, and carried
on explorations during the greater part of the year 1903.
Nothing is known of the equipment used in the earlier work.
So far as known, no ore was ever shipped, and the workings never
proceeded beyond the stage of exploration. The deepest shaft
is said to be 120 feet deep, with drifts and galleries of unknown
extent.
Geologic conditions. — ^The shales of the vicinity have the usual
bright-red to brownish-red color and dip 12 degrees toward the
north. At the mine they are traversed by a vertical north-south
fissure (PI. XXXII), along which the movement has been parallel
to the bedding, a nearly horizontal shove, or heave. This is in-
dicated by both the slickensided walls and breccia of the fault
and the abrupt termination of the fissure beneath undisturbed con-
formable shales above. The fault-breccia, varying from 6 inches
to 2 feet in thickness, and about 3 feet of each wall of the
fissure are composed of the dark-gray, nearly black, soft shale
referred to as carrying the ore. On each side of the fissure this
color quickly changes, after a little mottling of gray and red, into
the normal red color of the typical Brunswick shales. In the
different layers there is considerable irregularity in the distance
at which this change takes place, but the average is perhaps 3
feet from the walls of the fissure. The zone of blackened
^W. W. Clayton, History of Union and Middlesex Counties, New Jersey,
Philadelphia, 1882, p. 849.
'American Journal of Science, ist sen, vol. 2, 1820, p. 198.
154 THE STATE GEOLOGIST.
material traceable from the top of the fissure in a nearly horizontal
position to the westward probably indicates that the heave here
follows a bedding-plane. Owing to the indistinctness of the
exposure, however, it is impossible to determine this point
definitely. Locally the dark-gray shale is spotted and mottled
to a slight extent by white bleached areas. No trap debris is
visible about any of the workings, and probably none occurs here.
Character and occurrence of the ores, — The ore is native cop-
per, altered in part to civrysocolla (green copper silicate), in dark-
gray shale constituting the breccia and walls of a fault fissure.
There are also minute grains of chalcapyrite (brass-yellow
copper-iron sulphide) and of magnetite in the dark-colored shale.
The copper occurs as thin sheets and films in joint cracks of
the dark-gray shale and plating the slickensided surfaces of the
breccia and walls. In the form of minute grains and strings it
also permeates the mass of the shale and occasional bituminous
plant remains. ChrysocoUa is chiefly confined to the joints and
fissures, while chalcopyrite occurs very sparingly in minute dis-
seminated particles through the body of the shale.
Prospects.-^Mr, Thomas A. Edison, who did some work here
about twenty-five years ago, writes in answer to an inquiry : "The
ores were too lean to pay. Of the streak we worked, which was
about four feet wide, the average was about one-half per cent."
It is said that the last operations produced ore that averaged over
2 per cent., but authentic information to this effect is lacking.
At any rate there seems little probability that there is a great body
of ore at this place, such as a deposit of low grade would require
for profitable exploitation, and there is, therefore, no encourage-
ment for further expenditures in exploration.
COPPER ORES IN OTHER LOCAUTlES.
Copper ores at Glen Ridge, — Traces of old workings are still
to be seen at Glen Ridge, 4 miles northwest of Newark, in the
area just east of the public school building. CkdlcQcite (black
copper sulphide) and chrysocolla (the bluish-green silicate) are
found penetrating and largely replacing bituminous plant remains
Geological Survey, iqo6. PLATE XXXII.
Heave fault. Old copper n
fe* v
(•»r '.
•«*?■.
"-»»
!*»
t'.
TRIASSIC COPPER ORES. 155
in black glossy masses looking much like anthracite coal. Gray
sandstone is also stained green by impregnations of chrysocoUa,
as in the Arlington mine. No trap is known to occur here or in
the surrounding region for several miles, and local outcrops are
not sufficient to determine whether or not there are fault fissures
in the strata. Copper minerals in exactly the same association
are found in certain strata of the old sandstone quarries at Avon-
dale, north of Newark and Belleville, and also in a quarry a mile
and a half northeast of the Schuyler mine.
Copper and silver at Newtown, — Native silver in small scales
and specks occurs in gray sandstone stained with chrysocoUa on
George Drake's farm at Newtown, 4 miles north of New Bruns-
witk. Only surface specimens have been collected, and there has
been no prospecting for ores. As at Glen Ridge, described above,
no trap rocks occur here nor within a distance of several miles in
the adjacent regions.
Copper ores at Port Lee, — Small amounts of chalcopyrite (cop-
per pyrites), with some "malachite^' (probably chrysocolla, the
silicate) were discovered in the sandstones under the trap of the
Palisades at Fort Lee in very early times, and some exploratory
work was done in the hope of developing a gold mine.
On Pennington Mountain. — On the southern and southwestern
slopes of Pennington Mountain, i to 2 miles northwest! of
Pennington, traces of copper minerals have been found in the
altered shales adjacent to the intrusive trap mass which forms the
backbone of the mountain. These have led to occasional pros-
pecting operations on a small scale, but no notable amount of
ore has been located, nor is any to be expected.
Enough copper is often present to produce green chrysocoUa
stains in the shales and sandstones near the trap masses, both ex-
trusive and intrusive, but experience teaches that it is not wise
to base sanguine expectations of ore deposits on such "indi-
cations." Nothing illustrates better than such copper stains the
accuracy of the old precept that "one swallow doesn't make a
summer." At the various localities just described. Glen Ridge,
Newtown, Fort Lee, and Pennington Mountain, known condi-
tions give no reason to expect more than such scant discolor-
ations.
156 THE STATE GEOLOGIST.
ORIGIN OF THE NEWARK (TRIASSIC) COPPER ORES.
Whatever the economic aspects of these Triassic copper ores
they must continue to possess considerable scientific interest as
problems in ore-deposition. The comparatively simple structural
relationships of the ores and associated rocks relieves them of
the difficulties and uncertainties attendant upon the complicated
structures that prevail in many important mining districts. The
conclusions arrived at, when satisfactorily established, should
therefore be correspondingly simpler and clearer and should find
profitable application in regions where the problems are more
involved. It is largely with a view to the scientific value of the
deposits that these studies have been undertaken, and it is hoped
that the attention of geologists may be drawn to both the im-
portance and accessibility of these examples for the elucidation
of questions of ore genesis.
Kemp^ has suggested that the copper of these deposits has
probably come from the chalcopyrite disseminated through the
trap or from copper in the pyroxene of these rocks, but makes
no reference to mode of accumulation.
Weed's hypotliesis. — In 1902, Weed^ suggested the possibil-
ity of some close connection between igneous activities and the
origin of the ores associated with intrusive trap rocks. He says :
"At Rocky Hill glance and hematite occur under conditions that
suggest a hydrothermal origin, and at Arlington also the con-
ditions indicate a reimpregnation of the overlying rocks, with
subsequent slight alterations and migrations of the copper.''
Later, however, after an examination of the Rocky Hill mine,
he ascribes the ores to the influence of percolating surface waters
in the partial alteration of the trap. He says '?
*'The scientific interest of this deposit is very great on account
of the evident reducing action of the hornblende and chlorite
upon copper-bearing solutions, but the discussion of the origin
* Ore Deposits of the United States, 2d ed., p. 168 ; 5th ed., p. 223.
'Ann. Report State Geologist N. J. for 1902, p. 131.
• Bulletin U. S. Geological Survey No. 225, 1904, p. 189.
TRIASSIC COPPER ORES. 157
of the ore involves a consideration of the various cycles of up-
lift and erosion to which the region has been subjected since
Triassic time, and the accompanying movements of percolating
\vaters, which are supposed to have derived the copper from the
alteration of the trap from a fresh basaltic lava or diabase sheet
to its present somewhat altered condition."
This is the conclusion he had formerly arrived at in regard
to the ores beneath the trap sheet of First Mountain, an extru-
sive mass.^ For the latter he gives the following probable se-
quence of events: (a) Basalt chloritized, iron reduced from
silicate to ferrous oxide; (&) calcite amygdules formed in basalt
and pores of the altered shale bed; (c) copper dissolved out by
percolating waters and carried downward; (d) copper and cal-
cite deposited in pores of the ore; (e) glance reduced and ferric
oxide reduced in white patches. For this last step he finds that
"the readiest agent at hand to reduce the glance to native copper
is humic acid in waters containing oxygen," and "where organic
matter such as plant remains occurred, the copper sulphide would
be reduced to native copper." He further supposes that the solu-
tions carrying the copper "contained alkaline carbonates, and
precipitated copper and glance with calcite."
Objections to Weed's hypothesis, — ^Many of the difficulties in-
volved in the foregoing hypothesis were fully appreciated by the
author himself, who, after summing up the conditions of occur-
rence, states that "it is hard tO' see how any single chemical se-
quence can account for facts apparently so contradictory, and it
may be like Vogt's Norwegian cases, an example of reversed con-
ditions." He also demonstrates how impossible it is to adapt
the commonly accepted explanation of the Lake Superior ores to
the New Jersey deposits. He says :
"From the complete absence of iron oxide with the copper ore,
and from the fact that the native copper occurs only in those
portions of the ore-bed in which the ferric oxide has been re-
duced, a phenomenon common to Bolivian and European de-
posits as well as these, it is evident that the commonly accepted
explanation is not only not adequate, but contrary to the observed
^ Annual Report of the State Geologist of N. J. for 1892, pp. 136-139.
II GEOL
158 THE STATE GEOLOGIST.
facts. If it were the protoxide of iron or of magnetite ferrous
solutions that caused the reductions we should have red spots
and ferric oxide, one of the most insoluble and stable of sub-
stances, associated with the native copper."
Some further difficulties in the application of Weed's hypo-
thesis may be enumerated as follows :
( 1 ) The trap rock of First Mountain is not sufficiently altered
to account for the ores underlying it. On the basis of one-fortieth
of one per cent, of copper in the unaltered trap, one-fourth of
this would have to be transferred without loss from a trap sheet
600 feet thick, in order to supply two feet of the underlying
shales with an average of 2j4 per cent, of copper. The great
bulk of the trap is believed to be much less altered than this
supposition would demand.
(2) An intricate system of meteoric circulation would be re-
quired to account for the ores overlying the trap sheet on the
back of First Mountain and for the deposits above the intrusive
trap rocks at the Arlington and Rocky Hill mines. If these ores
have been derived from the alteration of the underlying trap
masses, as supposed by Weed, to supply those lying above the
First Mountain trap an upward movement of the copper-bearing
solutions is required, whereas exactly the reverse supposition has
been made in order to bring down the copper for the ores beneath
the trap.
(3) The ore at Arlington not only lies chiefly above the in-
trusive trap, but its amount is out of all proportion to the thin
sheets of this rock that have thus far been found in the vicinity
of the mine. No tests have been made to determine the copper
content of the unaltered portions of these traps, but unless this
should prove to be far in excess of examples thus far determined
in the New Jersey traps, the ore bodies here would not only
require all the copper from the accompanying dikes and sheets,
but in addition a much larger supply would be needed from some
unknown source.
(4) Weed supposes that the solutions carrying the copper
"contained alkaline carbonates, and precipitated copper and
glance with calcite" in a porous stratum of shale. An examina-
tion of the shales of the adjacent regions to the south and south-
TRIASSIC COPPER ORES. 159
west shows that the normal red Brunswick shales are often thickly
interspersed with thin tabular crystals and clusters of crystals of
calcite, which range in size from almost invisible to more than
an inch in diameter. This calcite, therefore, is a normal con-
stituent of the shales and has not been supplied from the trap,
and the peculiar slit-like pores in the shale of the upper oxidized
ores in the Somerville mine, are the result of leaching out of
these tabular calcites.
(5) Calcite occurring in amygdaloids and in fissures of the
trap and the shales has undoubtedly been derived, like the zeolites,
from the alteration of the trap rocks by percolating waters, and
is in no way to be associated m origin with the calcite in the
body of the shales. Such calcite with accompanying zeolites
doubtless began to form with the beginning of erosion and per-
colating waters inaugurated by the deformation of the Newark
strata, and continues to the present time.
(6) While the humic acid supposed to reduce the copper to
a native metallic state is presumably furnished by percolating
waters from the surface, it is also supposed that "where organic
matter, such as plant remains, occurred the copper sulphide would
be reduced to native copper." When present, orgianic matter
undoubte^ily produces these results, as shown by specimens ob-
tained at M'enlo Park and Glen Ridge, but the prevailing bar-
renness of the red Brunswick shales in this respect is well known.
Were it otherwise the well nigh universal ferric coloring would
present a chemical problem no less difficult than that of the cop-
per ores themselves. Practically no organic matter occurs in
the Somerville mine, replaced or otherwise, and the quantities
found in connection with other copper ores of the State are wholly
inadequate to account for more than a minute fraction of the
total deposit.
(7) Weed's hypothesis fails to account in any manner for
those ore-deposits that are in no way associated with trap rocks,
as at New Brunswick, Menlo Park, Glen Ridge and Newtown.
At all of these localities the underlying Palisades intrusive must
be some thousands of feet below, and the extrusive sheet of
First Mountain, if extended, would lie at a still greater distance
above. The only known nearer trap masses in any of these
i6o THE STATE GEOLOGIST.
cases are thin dikes and equally thin sheets sometimes connected
with them, and even these are seldom near.
A HYDROTHERMAIw HYPOTHESIS.
The copper ores lie in a broad curved belt (See map, PL
XXX) above the great intrusive sill of the Palisades and Rocky-
Hill and, with few small exceptions, below the extrusive trap
sheet of First Mountain. As explained in the preceding pages,
these deposits may be grouped into two general classes ; namely,
those with intrusive trap rocks and those without such associa-
tions. Of the latter, some are under or over the lowest extru-
sive sheet of the Watchungs, and others are out in the midst
of the broad shale areas entirely apart from trap rocks of any
kind. It is also clear, from the foregoing descriptions of the
various deposits, that the ores of each of the leading types are
remarkably uniform in character, the essential ore associated with
intrusives being chalcocite, or glance, while apart from such asso-
ciation native copper chiefly occurs.
Origin of ores zvith intrusive traps, — The close association of
these ores \vith intrusive sills, dikes and apophyses, and their
position chiefly above such intrusives in the Griggstown (Rocky
Hill) and Arlington mines leave little doubt that there is a genetic
connection. That this is not merely a derivation through later
alteration of the trap rocks by percolating waters and the simul-
taneous removal of the contained copper in solution is demon-
«
strated by two conditions referred to above, namely, the posi-
tion of the ores chiefly above instead of below the trap masses,
and the quantity of ore as compared with the small amount of
known trap rocks, especially at the Arlington mine.
Th'ere remains, therefore, the hypothesis of heated copper-
bearing solutions, and. possibly vapors, arising from the greater
underlying mass of intrusives along the dikes and accompanying
fissures, and depositing chalcocite in the immediate vicinity while
still highly heated. Under the great pressure of overlying forma-
tions and the cooling influence of the surrounding strata, vapors
probably could not exist more than a very short distance from
the greater intrusive masses ; and the chief effects may, therefore,
TRIASSIC COPPER ORES. i6i
be safely ascribed to solutions, probably magmatic waters emanat-
ing directly from the molten lava.
At the Griggstown mine and vicinity the Rocky Hill intrusive
sill, which lies but a few hundred feet below, sent up irregular
dikes and finger-like apophyses into the overlying shales. Some
of these now appear as the little round.ed outcrops of trap that
are scattered over this region. The shales are fissured but little,
and this was undoubtedly confined, in the main, to the immediate
vicinity of the intrusive. Shales more than a mile in thickness
overlie this region, and many parts of these are highly charged
with crystals of calcite. It is quite possible that some reaction of
the solutions with this mineral have contributed to the deposition
of the copper-bearing mineral, chalcocite.
At the Arlington mine the impregnated sandstone is penetrated
by dikes and by thin sheets along the bedding planes. The solu-
tions rose along the fissures of intrusion and their branchings in
the adjacent sediments and penetrated the breccias and porous
sandstones, impregnating them with ore. Doubtless waters also
rose to higher horizons and escaped freely to the surface or
formed ore deposits that have been subsequently removed by
erosion. Similar conditions also exist at Flemjngton, where the
ore-bearing solutions followed the intrusive dikes and accom-
panying fissures.
Origin of ores! zinthout associated intnisives, — It has been
demonstrated^ experimentally in the laboratory of the U. S.
Geological Survey that a solution saturated with cuprous sul-
phate will deposit metallic copper on cooling, and that, therefore,
a solution in which cupric sulphate has been partly reduced to
cuprous sulphate by ferrous sulphate, pyrite, chalcocite, siderite,
or silicates rich in ferrous iron, will deposit metallic copper if
carried to a cooler region. It was also shown that if silver
sulphate is present with the cuprous sulphate the silver will be
deposited, on cooling, before the copper, and, hence, the two
metals will appear in separate masses instead of combining to
form an alloy.
^H. N. Stokes, Economic Geology, vol. i, 1906, pp. 644-650.
i62 THE STATE GEOLOGIST.
In conformity with these results the Newark copper ores of
the second type (that is, apart from intrusive trap) .are readily
conceived to be deposits from waters heated by and probably
emanating from the great underlying intrusive trap sheet and its
various branchings and ramifications through the sediments.
Such waters must have permeated the strata over a wide area at
the time of the intrusion of the traps and during the long period
of slow cooling that followed, especially along the fissures and
joint-cracks of the overlying shales, sandstones, and extrusive
trap sheets. These waters were probably acid solutions of cu-
prous sulphate derived directly from the trap, and carrying a little
silver and a trace of gold in solution. Their movements through
the sediments were sufficiently obstructed in certain localities to
permit a considerable accumulation of deposits through progres-
sive cooling.
Probably these deposits were also augmented at times by
chemical reactions between the solution and certain constituents
of the inclosing rocks. As already described, the typical shales
of this region are often more or less calcareous and contain
minute crystals and small clusters of tabular calcite disseminated
through them. Observations in many well-known mining regions
have demonstrated the efficacy of this mineral as a precipitating
agent in the formation of ore-deposits wherever the solutions are
sufficiently retarded in their movements to permit the reactions to
occur. At the same time the calcite would be thus removed in
part, leaving the characteristic hollow, slit-like spaces more or
less occupied by copper or copper-bearing minerals. In the same
manner the ferric oxide coloring matter of the red shales has
been leached out by the acid waters, leaving the grayish and
whitish spots that mark the impregnated portions of the rock.
Such waters as escaped upward through the more extensive
dislocations were intercepted in the vicinity of Somerville, Bound
Brook and Plainfield by the extrusive trap sheet of First Moun-
tain, and thus the layer of shale immediately beneath became
charged with metallic copper. Some portions of the solution,
however, found passage through the joints and fissures in the
trap; and thus metallic copper is found in the midst of the trap
TRIASSIC COPPER ORES. 163
in the quarries at Chimney Rock, and small amounts of ore occur
on top of the trap sheet of First Mountain and beneath the over-
lying shales of Washington Valley, at intervals from Pluckemin
to Feltville.
At New Brunswick the underlying Palisades-Rocky Hill intru-
sive trap sill is probably as near as at the Arlington mine, and
dikes that penetrate the shales to within a short distance of the
city to the east, south and southwest, give evidence of widespread
Assuring. Heavy ledges of sandstone underlie the shales at this
place, as seen in the old quarries at the boat landing. The native
copper and various secondary minerals derived from it, however,
are in joints and fissures of the impervious overlying shales.
Similar conditions seem to have prevailed at Newtown, where
native silver is found associated with copper ores. The ores
found at Glen Ridge are also doubtless of exactly the same char-
acter. The deposits in this case may have been fed by an exten-
sion of the same system of fissures through which the Arlington
ores were brought up.
At Menlo Park the ores are confined to the breccia and walls
of a well-marked heave-fault, through which the ore-bearing
solutions must have come; and the abrupt termination of the
fissure above makes it reasonably certain that they could only
have come upward. At this and several other localities occasional
bits of bituminous vegetable remains are found more or less
infused with copper-bearing minerals, but not more so than much
of the adjacent rock that is entirely barren of such materials;
and in no case could the organic matter, even if all replaced,
account for more than a very small amount of the ore actually
deposited.
Summary of origin, — In all cases the Newark (Triassic) cop-
per ores of New Jersey are attributable to the same source,
namely, hot copper-bearing solutions, doubtless magtnatic waters,
deriving both their heat and their copper salts from the great
underlying Palisades-Rocky Hill trap sill and its offshoots. The
deposition of chalcocite in the heated portions near the intrusives
and of native copper with a little chalcocite in the more remote,
and, therefore, cold regions may, in both cases, have been chiefly
i64 THE STATE GEOLOGIST.
the result of cooling, supplemented perhaps in part by reactions
with the widespread calcite of the sedimentary rocks. The con-
ditions of extensive accumulation have been supplied by some
relatively impervious member, a dense shale or a trap sheet,
which has sufficiently impeded the movements of the uprising
solutions to permit considerable cooling, and, therefore, extensive
deposits, and also to allow time for possible reactions with the
calcite of the sediments, and for leaching out the ferric coloring,
in part, by the acid waters.
AGE O^ THE COPPER ORES.
From the foregoing descriptions of the various ore deposits of
this region it is clear that in many localities they are closely asso^
ciated with the great Palisades-Rocky Hill instrusive trap sill, as
at Griggstown, southwest of New Brunswick, and at Arlington.
It is equally evident that the deposits along First Mountain, as
at Somerville, Bound Brook and Plainfield, are of later origin
than the overlying trap sheet, for they penetrate the trap itself,
and small deposits of ore are found above the trap sheet and be-
neath the overlying shales.
The time of deposition of the ores is therefore correlated with
the intrusion of the Palisades sill, which is regarded as their
source, and subsequent to the extrusive flows of the Watchung
Mountains. Other reasons for placing the date of the intrusive
trap after the extirusives are discussed on pages 125-127. The
ores were formed, therefore, very near the close of the Newark de-
position in this region, and the great igneous intrusion may well
have marked the beginning of those disturbances that led to the
tilting and faulting of the whole series.
April 10, 1907.
Properties of Trap Rocks for Road Construction*
BY J. VOI.NEY LEWIS.
Crushed trap rock for road construction was produced to the
value of more than half a million dollars a year by the quarries of
the State during the years 1903 and 1904, in addition to large
amounts for railroad ballast and for concrete. The merits of
this stone for the building of macadam roads have become gen-
erally known throughout the country, but it is not all equally
adapted for all roads, as abundantly demonstrated by both ex-
perience and laboratory tests of the stone from the various
quarries. Hence it was deemed advisable, in connection with the
study of the geology and petrography of the trap rocks, to collect ^
specimens from the more accessible localities and submit these to
the Office of Public Roads, Department of Agriculture, Washing-
ton, D. C, for systematic examination of their properties for
road construction.
The accompanying table and diagram represent the results of
these tests, including some half a dozen samples that had been
previously submitted by others. In the column designated
"French coefficient of wear," the higher the number the more
durable the rock; higher values also indicate superior '^Hardness"
and "Toughness" in the next two columns. Under "Cementing
value" the higher numbers show greater binding power of the
finely powdered material. In further explanation of these proper-
ties as affecting the adaptability of a stone for road building, the
following is quoted from Mr. L. W. Page, Director of the Office
of Public Roads '}
* Yearbook of the U. S. Department of Agriculture for 1900, p. 351.
(i6s)
i66 THE STATE GEOLOGIST.
"By hardness is meant the power possessed by a rock to resist the wearing
action caused by the abrasion of wheels and horses* feet. Toughness, as
understood by road builders, is the adhesion between the crystals and fine
particles of a rock, which gives it power to resist fracture when subjected to
the blows of traffic. This important property, while distinct from hardness,
is yet intimately associated with it, and can, in a measure, make up for a
deficiency in hardness. Hardness, for instance, would be the resistance
offered by a rock to the grinding of an emery wheel ; toughness the resistance
to fracture when struck with a hammer.
"Cementing or binding power is the property possessed by the dust of a
rock to act after wetting as a cement to the coarser fragments composing
the road, binding them together and forming a smooth, impervious shell over
the surface. Such a shell, formed by a rock of high cementing value, protects
the underlying material from wear and acts as a cushion to the blows from
horses' feet, and at the same time resists the waste of material caused by
wind and rain, and preserves the foundation by shedding the surface water.
Binding power is thus probably the most important property to be sought for
in a road-building rock, as its presence is always necessary for the best
results.
"The hardness and toughness of the binder surface more than of the rock
itself represents the hardness and toughness of the road, for if the weight
of traffic is sufficient to destroy the bond of cementation of the surface, the
stones below are soon loosened and forced out of place. When there is an
absence of binding material, which often occurs when the rock is too hard
for the traffic to which it is subjected, the road soon loosens or ravels.
"Experience shows that a rock possessing all three of the properties men-
tioned in a high degree does not under all conditions make a good road
material; on the contrary, under certain conditions, it may be altogether
unsuitable. As an illustration of this, if a country road or a city parkway,
where only a light traffic prevails, were built of a very hard and tough rock
with a high cementing value, neither the best, nor, if a softer rock were
available, would the cheapest results be obtained. Such a rock would so
effectively resist the wear of a light traffic that the amount of fine dust worn
off would be carried away by wind and rain faster than it would be supplied
by wear. Consequently, the binder supplied by wear would be insufficient, and
if not supplied from some other source the road would soon go to pieces.
The first cost of such a rock would in most instances be greater than that of
a softer one, and the necessary repairs resulting from its use would also be
very expensive. * * *
"The degree to which a rock absorbs water may also be important, for in
cold climates this to some extent determines the liability of a rock to fracture
by freezing. It is not so important, however, as the 'absorptive power of the
road itself, for if the road holds much water the destruction wrought by
frost is very great. This trouble is generally due to faulty construction
rather than to material. The density or weight of a rock is also considered
of importance, as the heavier the rock the better it stays in place and the
better it resists the action of wind and rain."
TRAP ROCK FOR ROADS. 167
THE SELECTION OF A STONE I^OR MACADAM ROADS.
As stated above, a stone of the greatest hardness, toughness,
and cementing power does not make the best road under all cir-
cumstances ; in fact such material would give the best results only
under the most severe conditions of heavy traffic. It is equally
true that a stone of the same general kind or class does not
always possess these properties in the same degree. The trap
rocks, for instance, vary greatly in their texture, chemical com-
position, and degree of alteration, and these variations affect
to a marked degree the properties of the stone for road con-
struction.
The trap rock produced by the various quarries varies from
exceedingly dense, fine-grained and even partly glassy condition
to a coarse-grained, granitic texture, in which the individual
minerals are developed in grains of one-fourth of an inch or
more in diameter. Under the microscope the "habit" of the
mineral particles is seen also to vary greatly ; in some cases they
are of about equal" dimensions in every direction, tending toward
a rounded form, in others they are greatly elongated, lath-shaped
and rod-shaped forms. Other things being equal, fine-grained
varieties and those composed of interlocking, elongated minerals
possess a higher degree of toughness.
Variations in chemical composition are accompanied chiefly
by corresponding variations in the proportions of the minerals
pyroxene and feldspar (labradorite), the two principal constitu-
ents of the trap rocks of this region. Of these the former pos-
sesses the greater toughness and the latter the greater hardness.
In some of the more basic varieties olivine (chrysolite) may con-
stitute as much as 10 per cent, of the rock. This mineral is
somewhat harder even than the feldspar, but it is usually more
or less altered into serpentine, which is considerably softer. The
pyroxene is also subject to extensive alteration into greenish
chloritic minerals, which are also much softer than the original
mineral. The feldspar is somewhat less subject to extensive
alteration, but is often partly changed into a soft white powdery
kaolin.
i68 THE STATE GEOLOGIST.
Thus it will be readily understood that while some trap rocks
are very hard and tough and suited only for heavy-traffic roads,
there are others that are not suited to such severe conditions and
are better adapted to suburban streets, park ways, and country
roads. Too often, however, the selection of the material for
road building is made solely with a view to convenience or cheap-
ness of the stone, with the result that an inferior road is con-
structed and the economy in first cost is more than counter-
balanced by the expense of maintenance. Such initial careless-
ness mav result in the selection of a stone that is too hard and
tough for the traffic to which it is subjected or one that is too
soft and brittle.
"If the surface of a macadam road continues to be too muddy or dusty
after the necessary drainage precautions have been followed, then the rock
of which it is constructed lacks sufficient hardness or toughness to meet the
traffic to which it is subjected. If, on the contrary, the fine binding material
of the surface is carried off by wind and rain and is not replaced by wear of
the coarser fragments, the surface stones will soon loosen and allow water
to make its way freely to the foundation and bring about the destruction of
the road. Such conditions are brought about by an excess of hardness or
toughness of the rock for the traffic. Under all conditions a rock of high
cementing value is desirable; for, other things being equal, such a rock
better resists the wear of traffic and the action of wind and rain."
The different classes o-f traffic have been divided into- five
groups, according to volume and character, as follows :
1. City traffic, such as exists on the business streets of large
cities. The conditions are too severe for any macadam, and more
resistant forms of pavement must be used.
2. Urban traffic, that of the less severe city conditions, but
subjected to heavy traffic and requiring the hardest and toughest
macadam.
3. Suburban traffic, that of suburbs of larger cities and main
streets of country towns, requiring a macadcim of high tough-
ness but somewhat less hardness than the preceding.
4. Highway traffic, such as exists on the principal country
roads. A rock of»medium hardness and toughness is best.
5. Country-road traffic, that of the less frequented country
roads. For this it is best to use a comparatively soft rock of
medium toughness.
TRAP ROCK FOR ROADS.
169
In the diagram, figure 9, the Scimples are arranged according
to the French coefficient of wear, beginning with the greatest
Pig. p.
Diagram showing tests on trap rock as road metal.
and decreasing toward the right, while hardness, toughness, and
other properties vary irregularly. Therefore those stones that
lyo THE STATE GEOLOGIST.
fall on the left-hand side and toward the middle of the diagram
and show at the same time great hardness and toughness are best
adapted to urban and other very heavy-traffic uses; while those
in the middle of the diagram with moderate hardness and tough-
ness, and toward the left with lower or toward the right with
higher values of these properties, are suitable for suburban and
heavy-traffic highway purposes. Those toward the right-hand
side with medium and further to the left with low hardness and
toughness are adapted to lighter suburban and ordinary high-
way traffic conditions. Even the softest and most brittle material
in the list is too resistant for the best results on the less fre-
quented country roads, unless combined with softer materials
to furnish the necessary fine powder for cementing.
It should be a matter of interest to all who are in any way
responsible for road construction or maintenance, as well as to
owners of quarries supplying road materials, to know that the
U. S. Department of Agriculture has a fully equipped road-
material laboratory, where any person residing in the United
States may have tests made free of charge by applying for in-
structions to the Office of Public Roads, Dept. Agriculture, Wash-
ington, D. C. Acknowledgements are due to Mr. L. W. Page,
director of this office, for the valuable data presented in the
accompanying table and for many courtesies extended during
the collection and testing of the materials.
April ID, 1907.
TRAP ROCK FOR ROADS.
171
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THE STATE GEOLOGIST.
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PART IV.
Notes on the Mining Industry*
By HENRY B. KUMMEL.
(173)
12 GEOL,
Notes on the Mining Industry*
BY HENRY B. KUMMEl^.
THE IRON MINES.
During 1906 the following iron rhines were producers: the
Washington and Ahles, at Oxford ; the Hurd, Richard and Hoff,
at Wharton; the Mount Hope mines, at Mount Hope; the
Hude, at Stanhope; the Andover, DeCamp, Upper Wood and
Wharton, at Hibemia; the Dickerson, at Ferro Mont; and the
Peters, at Ringwood. Development has been carried forward
at the Teabo and Scrub Oak or Dell, but these are not yet to be
classed as producers.
The total product during the year was 542,488 long tons, a
gain over the figfures of 1905. The steady increase since 1897 in
production as shown by the figures on page 180 are certainly
encouraging. The value of the ore at the mines is estimated at
$1,560,000.
At the Ahles mine, Oxford, of the Basic Iron Ore Company,
mining has been carried on from No. i and No. 3 shafts and
Slope No. 4 has been sunk so that it is expected to reach ore
early in 1907. As has been mentioned in previous reports, the
ore from this mine is a mixture of magnetite and limonite, carry-
ing about 4 per cent, of manganese. With the completion of the
new slope, it will be possible to increase very largely the annual
output. The ore is mined by the caving system.
The Empire Steel and Iron Company, of Catasauqua, Pa., are
operating only the Washington mine at Oxford, and have done
considerable development work in that vicinity, and from present
indications the output of this mine will be largely increased and
its grade of ore raised when contemplated improvements are
(175)
176 THE STATE GEOLOGIST.
completed. At Mount Hope a new shaft, the Leonard, has been
opened to mine ore from the Side Hill vein and the Findley vein,
and it is planned to sink a new shaft on the Brannin vein. The
Elizabeth mine has been a producer during the year.
The Musconetcong Iron Company, at Stanhope, has continued
to operate the Hude mine at Stanhope, and also the Dickerson
mine at Ferro Mont, but both mines were only small producers.
The Richard mine, owned by the Thomas Iron Company of
Easton, has continued to be a large producer and has maintained
the high record of tonnage of the last few years.
At the Hoff mine, at Wharton, which was reopened in 1905
by the Hoff Mining and Realty Improvement Co. of Rockaway,
N. J., the raising of ore has continued and a new tunnel has been
started on another vein about half a piile from the old mine.
All the Joseph Wharton properties have been the scene of
activity and development. The improvements at the Hurd mine
at Wharton, commenced in 1905, were carried forward with the
result that that mine is now a larger producer than for many
years previous. At the Hibernia mines a new ore body has been
located a few hundred feet northwest of the one heretofore
worked. At a depth of 75 feet on the dip, lean ore containing
about 30 to 32 per cent, of iron was crosscut for a distance of
35 feet. Further exploratory work upon this body will be made
this year. The Scrub Oak or Dell mine, northwest of Mine Hill,
has been pumped out and explored and a new shaft is being
sunk to a large body of low-grade ore. At the Teabo mine a
crosscut at the 800-foot level of the new shaft struck a 2-foot
vein of rich magnetite at a distance of 27 feet in the hanging
wall, and a thicker ore body on the footwall side at a distance
of about 40 feet from the shaft. The shaft was then sunk 40
feet and crosscutting was again commenced to these ore bodies.
THE ZINC MINES.
The New Jersey Zinc Company's mines at Franklin have
shown a large increase in production over that of 1905. During
the first part of the year most of the ore obtained came from the
drives extended along the various levels, as in former years. In
NOTES ON THE MINING INDUSTRY.
177
the latter part of the year, however, considerable ore was broken
from the open cut at the extreme south end of the ore body.
Cableways, with the necessary bins, were erected, and these are
expected to handle the ore which lies south of "The Dike."
A new shaft has been started, which, going down at an angle of
47J^° in the footwall rock, will command the full depth of the
deposit and deliver the ore directly into the mill. Very con-
siderable extensions and additions to the plant are contemplated.
The company reports a total of 361,330 tons of ore mined
during 1906.
THE UMESTONE INDUSTRY.
In the Annual Report for 1905, the chemical composition of the
white limestone of Sussex and Warren counties was discussed
at some length, and a map published showing the distribution of
the most important areas. The demand for this rock has so in-
creased that the Survey proposes hereafter to compile annually
statistics and a brief summary of the industry.
Qimrries, — ^During 1906, the following firms were quarrying
the crystalline limestone :
No
■ of
OMce.
Quarries. Location,
Chief Use.
Bethlehem Steel Co.
South Bethlehem
McAfee
Flux
Bigelow & Swain
Newark
Ogdensburg,
Portland cement
*
-
and flux
Crestmore Stone Co.
Dover
Pinkneyville,
Portland cement
Edison Portland
and flux
Cement Co.
Stewartsville
I*
((
Portland cement
N. H. Hunt
Newton
((
Flux and cement
New Jersey Lime Co.
McAfee
3
Hamburg and
McAfee
Lime
B. Nicoll & Co.
New York
3
Franklin
Furnace
Flux
The Windsor Lime Co.
Newark
I
Hamburg
Lime
Prodtict, — The total production during the year, as compiled
from reports furnished the State Geologist by the producers, was
459,927 tons. These figures are only approximately correct.
* In November the Crestmore Stone Company's quarry was leased by the
Portland Cement Company.
178 THE STATE GEOLOGIST.
inasmuch as the returns frohi at least three sources were g^ven
in round numbers to the nearest thousand, and in one or two
other instances only to the nearest hundred tons. However, the
figures cannot be far from; the truth, and can be accepted as
substantially correct, the probable error being less than one-half
of one per cent.
Uses. — It is not possible to determine from the returns the
rjespective amounts used for various purposes. Apparently by
far the largest part is used as a flux, both in blast furnaces and
open-hearth steel furnaces. The demand for Portland Cement is
also large, and less than 15 per cent, is burned for lime.
Nem qtutrries. — ^The quarry of Bigelow & Swain was opened in
July, so that the output there was for but a part of the year.
According to 16 analyses furnished the Survey by this firm,
the rock of their quarry, omitting one special sample, has the
following constitution :
Maximum. Minimum.
Silica, 0.82 0.32
Iron Oxide and Alumina, 0.90 0.20
Carbonate of Lime, 97-31 94.23
Carbonate of Magnesia, 4-57 i-43
One hundred and three carloads of rock shipped the Thomas
Iron Company were reported to average only 0.55 per cent silica.
These facts confirm the conclusions published in the Annual
Report for 1905, that much of the white limestone is a very pure
non-dolomitic limestone, and also indicate that the fresh rock
obtainable in a quarry may be purer than indicated by analyses
of samples taken from surface ledges.^
March 15, 1907.
* Compare Analysis No. 21, p. 184, Annual Report of the State Geologist,
1905.
Mineral Statistics^
For the Year J906.
IRON ORE.
The total production of the mines, as reported by the several
mining companies, was 542,488 tons.
The table of statistics is reprinted, with the total amount for
1903 added.
TABLE OF STATISTICS.
Year. Iron Ore. Authority.
1790 10,000 tons Morse's estimate.
1830 20,000 tons Gordon's Gazetteer.
1855 100,000 tons Dr. Kitcheirs estimate.
i860 164,900 tons U. S. census.
1864 226,000 tons Annual Report State Geologist.
1867 275,067 tons " " "
1870 362,636 tons U. S. census.
1871 450,000 tons Annual Report State Geologist.
1872 600,000 tons
1873 665,000 tons
1874 525,000 tons
1875 390,000 tons
1876 285,000 tons
1877 315,000 tons*
1878 409,674 tons*
1879 488,028 tons
1880 745,000 tons
1881 737,052 tons
1882 932,762 tons
1883 521,416 tons
1884 393,710 tons
1885 330,000 tons
1886 500,501 tons
1887 547,889 tons
1888 447,738 tons
(( (( ((
(( (( ((
(( « «
(( ({ ((
(( (( li
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* From statistics collected later.
(179)
i8o THE STATE GEOLOGIST.
Year. Iron Ore. Authority.
1889 482,109 tons Annual Report State Geologist.
1890 .552,996 tons
1891 551,358 tons
1892 465455 tons
1893 356,150 tons
1894 277,483 tons
1895 282,433 tons
1896 264,999 tons
1897 257,235 tons
1898 275,378 tons
1899 300*757 tons
1900 342,390 tons*
1901 401,151 tons
1902 443,728 tons
(( (( K
(( « , «
It H it
it (( u
it ft a
u it tt
ti It tt
tt ti tt
tt tt tt
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1903 484,796 tons* " ^ " "
1904 499,952 tons
1905 500,541 tons
1906 542,488 ton^
(( (( tt
tt tt ti
tt tt tt
ZINC ORE.
The production of the New Jersey Zinc Company's mines is
reported by the company to be 361,330 gross tons of zinc and
franklinite ore. It was chiefly separated at the company's mills.
This report shows a gain in production over 1905 of 38,268 tons.
The statistics for a period of years are reprinted from the
last annual report.
ZINC ORE.
Year. Zinc Ore, Authority.
1868 25,000 tonsf Annual Report State Geologist.
1871 22,000 tonsf
1873 17,500 tons
1874 13,500 tons
1878 14,467 tons
1879 21,937 tons
1880 28,311 tons
1881 49,178 tons
1882 40,138 tons
1883 56,085 tons
(( it tt
(( tt It
(( it (t
(( tt (t
It tt ((
« tt it
it if it
it it it
ii it it
* The figures, 407,596 tons, given in the report for 1900, included 75,206 tons
of crude material which should have been reduced to its equivalent in con-
centrates. The figures for 1903, given in the report for that year, were incor-
rect.
t Estimated for 1868 and 1871. Statistics for 1873-1890, inclusive, are for
shipments by railway companies. The later reports are from zinc-mining
companies.
MINERAL STATISTICS. i8i
Year, Zinc Ore, Authority.
1884 40,094 tons Annual Report State Geologist.
1885 38,526 tons
1886 43,877 tons
1887 50,220 tons
1888 46,377 tons
1889 56,154 tons
1890 49,618 tons
1891 76,032 tons
1892 77,298 tons
1893 55,852 tons
1894 59,382 tons
1895*
1896 78,080 tons
1897 76,973 tons
1898 99419 tons
1899 154,447 tons
1900 194,881 tons
1901 191,221 tons
1902 209,386 tons
1903 279419 tons
1904 250,025 tons
1905 323,062 tons
1906 361,330 tons
(( ({
» it
tt it
(t it
tt ft
tt tt
tt ' ((
{( ((
(( ({
tt tt
tt tt
tt It
tt tt
tt tt
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* No statistics were published in the Annual Report for 1895.
Publications^
It is the wish of the Board of Managers to complete, so far
as possible, incomplete sets of the publications of the Survey,
chiefly files of the Annual Reports ' in public libraries, and
librarians are urged to correspond with the State Geologist con-
cerning this matter.
The Annual Reports of the State Geologist are printed by
order of the Legislature as a part of the legislative documents.
They are distributed by the State Geologist to libraries and public
institutions, and, so far as possible, to any who may be interested
in the subjects of which they treat.
Six volumes of the Final Report series have been issued.
Volimie I, published in 1888, has been very scarce for several
years, but all the valuable tables were reprinted in an appendix
of Volume IV, of which a few copies still remain, although the
supply of this volimie is so far reduced that indiscriminate re-
quests cannot be granted.
The appended list makes brief mention of all the publications
of the present Survey since its inception in 1864, with a statement
of the editions now out of print. The reports of the Survey are
distributed without further expense than that of transportation.
Single reports can usually be sent more cheaply by mail than
otherwise, and requests should be accompanied by the proper
postage as indicated in the list. Otherwise they are sent express
collect. When the stock on hand of any report is redttced to 200
copies, the retnaining volumes are withdrawn from free distri-
bution and are sold at cost price.
The maps are distributed only by sale, at a price, 25 cents per
sheet, to cover cost of paper, printing and transportation. In
order to secure prompt attention, requests for both reports and
mtips should be addressed simply "State Geologist," Trenton,
N.J.
(183)
i84 THE STATE GEOLOGIST.
CATAU)GUE OF PUBUCATIONS.
Geoi^ogy of New Jersey. Newark, 1868, 8vo., xxiv + 899 pp. Out of print.
PoRTFouo OF Maps accompanying the same, as follows :
1. Azoic and paleozoic formations, including the iron-ore and limestone dis-
tricts ; colored. Scale, 2 miles to an inch.
2. Triassic formation, including the red sandstone and trap-rocks of Central
New Jersey; colored. Scale, 2 miles to an inch.
3. Cretaceous formation, including the greensand-marl beds ; colored. Scale,
2 miles to an inch.
4. Tertiary and recent formations of Southern New Jersey ; colored. Scale,
2 miles to an inch.
5. Map of a group of iron mines in Morris county; printed in two colors.
Scale, 3 inches to i mile.
6. Map of the Ringwood iron mines ; printed in two colors. Scale, 8 inches
to I mile.
7. Map of Oxford Furnace iron-ore veins; colored. Scale, 8 inches to i
mile.
8. Map of the zinc mines, Sussex county ; colored. Scale, 8 inches to i mile.
A few copies can be distributed at $2.00 per set.
Report on the Clay Deposits of Woodbridge, South Amboy and other
places in New Jersey, together with their uses for firebrick, pottery, etc.
Trenton, 1878, 8vo., viii + 381 pp., with map. Out of print.
A Preuminary Catalogue of the Flora of New Jersey, compiled by N. L.
Britton, Ph.D. New Brunswick, 1881, 8vo., xi -f 233 pp. Out of print.
Final Report of the State Geologist. Vol. I. Topography. Magnetism.
Climate. Trenton, 1888, 8vo., xi -f 439 pp. Out of print.
FtNAL Report of the State Geologist. Vol. II. Part I. Mineralogy.
Botany. Trenton, 1889, 8vo., x + 642 pp. Unbound copies, postage 22 cents.
Bound copies, $1.50.
Final Report of the State Geologist. Vol. II. Part II. Zoology. Tren-
ton. 1890, 8vo., X -f- 824 pp. (Postage, 30 cents.)
Report on Water- Supply. Vol. Ill of the Final Reports of the State
Geologist. Trenton, 1894, 8vo., 3Cvi + 352 and 96 pp. (Postage, 21 cents.)
Report on the Physical Geography of New Jersey. Vol. IV of the Final
Reports of the State Geologist. Trenton, 1898, 8vo., xvi + 170 -f- 200 pp.
Unbound copies, postage 24 cents; cloth bound, $1.35, with photo-relief map
of State, $2.85. Map separate, $1.50. Scarce.
Report on the Glacial Geology of New Jersey. Vol. V of the Final Re-
ports of the State Geologist. Trenton, 1902, 8vo., xxvii + 802 pp. (Sent by
express, 35 cents if prepaid, or charges collect.)
Report on Clays and CJlay Industry of New Jersey. Vol. VI. of the Final
Reports of the State Geologist. Trenton, 1904, 8vo., xxviii + 548 pp. (Sent
by express, 30 cents if prepaid, or charges collect.)
Brachiopoda and Lamellibanchiata of the Raritan Clays and Greensand
Marls of New Jersey. Trenton, 1886, quarto, pp. 338, plates XXXV and Map.
(Paleontology, Vol. I.) (By express.)
PUBLICATIONS. 185
GASTEROFO0A AND C£PHAix)PODA of the Raritan Clays and Greensand Marls
of New Jersey. Trenton, 1892, quarto, pp. 402, plates L. (Paleontology, Vol.
II.) (By express.)
Pai^sozoic Pai,eontology. Trenton, 1903, 8 vo., xii + 462 pp., plates LIU.
(Paleontology, VoL III.) (Postage, 20 cents.)
Ati^s op New Jersey. The complete work is made up of twenty sheets,
each about 27 by 37 inches, including margin. Seventeen sheets are on a scale
of I inch per mile and three on a scale of 5 miles per inch. It is the purpose
of the Survey gradually to replace Sheets i- 17 by a new series of maps, upon
the same scale, but somewhat differently arranged so as not to overlap. The
new sheets will be numbered from 21-37, ^^^ will be subject to extensive
revision before publication. These sheets will each cover the same territory
as eight of the large maps, on a scale of 2,000 feet per inch. Nos. i| 2, 4, 5, 7,
8, II, 12, 13 and 17 have already been replaced as explained below.
No, 9. Monmouth Shore, with the interior from Metuchen to Lakewood.
No, JO, Vicinity of Salem, from Swedesboro and Bridgeton westward to the
Delaware.
No, 14. Vicinity of Bridgeton, from AUowaystown and Vineland southward
to the Delaware bay shore.
No, 18, New Jersey State Map, Scale, 5 miles to the inch. Geographic.^
No. 19. New Jersey Relief Map. Scale, 5 miles to the inch. Hypsometric
No, 20, New Jersey Geological Map, Scale, 5 miles to the inch. (Out of
print.)
No, 21, Northern Warren and Western Sussex counties. Replaces Sheet i.
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Replaces Sheet 13.
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*At the date of preparing this report this sheet is out of print. A new
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April 15th, 1907.
1 86 THE STATE GEOLOGIST.
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ANNUAI, REPORTS.
Report of Professor George H. Cook upon the Geological Survey of New
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The Annual Report of Prof. Geo. H. Cook, State Geologist, to his Ex-
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Joel Parker, President of the Board of Managers of the Geological Survey of
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Annual Report of Prof. Geo. H. Cook, State Geologist, on the Geological
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Trenton, 1868, 8vo., 28 pp. Out of print.
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INDEX.
A.
Page
Ahles mine, 175
Andover mine (see Hibernia).
Argillite, tests on, 30, 76
Arlington copper mine, 140, 141, 143
trap dikes at, z 19, 12a
Artesian wells, report on 13
Assistants on Survey, 3
Avondale, copper near, 155
test of stone from, 64
Azurite 135, 136, 152
B.
Baldpate Mountain, 120
Bartle, W. E., test of stone from, 60
Bayley, W. S 12
Bayliss, Geo., test of stone from 66
Bellville Stone and Quarry Co., test of
stone from, 64
Bench-marks, changes of 9
Berryi E. W 16
Bethlehem Steel Co., white limestone
of, 177
Bigelow & Swain, white limestone of, 178
Board of Managers, changes in, 3
Bogota trap dike, 119, 122
Bound Brook Crushed Stone Co., trap
tests, 172
origin of ore at 162
Bridgewater copper mine 145
Buckley, tests on stone by 20
Building stone, report on, xo, 17
results of tests, 23
samples tested, 22
Byram, 117
C.
Caldwell, well near, no
Calcite, precipitation of ore by 162
Carteret, wells at 118
Cementing power of road metal, 166
quality of trap, 171
Chalcocite, 135, 138, 141, I44, I47, I5i» I54
Chalcopyrite,...i34, 138, 14s, i47. iS4i iSS
Chimney Rock, copper mines near,. 146, 149
ore at, 147
ChrysocoUa, 135,
138, 142, 14s, 147, 152, 154, 155
Page
Clay in glass sand, 83
Ooster, test of stone from, 68
Collections geological, 6
Commonwealth Quarry Co., trap rock
tests, 172
Cooper, E. E., trap rock tests, 172
Copper-bearing minerals, 134
Copper minerals in shale, 135
Copper, native, 135, 142, 147, 151, 154
Copper ores, age of, 164
mode of occurrence 136
origin of, 97, 156, 163
report on, 131
summary of origin 163
thickness of 143,
I4S» 147, ISO, 152, IS4
Copper, per cent, in shale 149
report on, 10
Correlation of intrusive trap sheets,... 120
trap sheets, zi6
Correspondence, 7
Cranberry Lake, tests of stone from,.. 34
Crestmore Stone Company, white lime-
stone of, 177
Cuprite 136, 138, 142, 145, 147, 152
Cuprous sulphate, copper from, x6i
Cushetunk trap, 122
Cutting, tests on stones by, 20
D.
Dana, J. D.> cited 105
DeCamp mine (see Hibernia).
DeGraves Bros., test of stone from,.. 54
Dell mine (see Scrub Oak) 176
Diabase, tests on, 28, 50, 52
Diamond drilling, cost of 8
Dickerson mine, 175, 176
Dover, test on stone from 40
E.
East Livingston, well near iii
Edison Portland Cement Company,
white limestone of, 177
Elizabeth mine 176
Employees on Survey, 3
13 GEOL
(189)
igo
INDEX.
F.
Page
Fanning, Thos., test of stone from, ... 40
Faults in Triassic, 127
age of, 129
overthrusts, 15
Federal Hill Granite Company, test of
stone from, 38
Feltville, 151
Ferguson, W. A., trap rock tests, 171
Ferric oxide, leaching out of, 162
Fire tests on building stones, 33
methods of making az
First Mountain, origin of flow, 124
Flemington copper mine 144. X45
Fort Lee, copper near, 155
Francisco Bros., trap tests, 171
Franklin Furnace, test of stone from,. 70
French copper mine, 151
Fresh Ponds, wells at, 1x9
Q.
Gage, R. B., 12, 79
Gamble & Son, tests of stone from,... 68
Geological collections, 6
German Valley, test of stone from 3*
Glass sand, amount produced, 9^
analyses of, 90, 92* 93
areas of, 80
cost of, 94
chemical composition, 89
description of deposits, ... 82
effect of iron in 9^
elimination of iron, 9^
impurities in, 89
industry, condition of, 79
methods of mining 84
mineral composition 91
prices of, 80
producers of, 95
report on, la
shape of grains 86
size of grains, 87
table of sixes, 88
washing, 85
whiteness of, 9*
Glen Ridge, copper at, iS4
Gneisses, tests on, 23,
36, 34. 36, 40, 4a. 46, 48
Gold at Arlington copper mine, i43
Granite-gneiss, tests of 38
Granites, tests of, «6
Gr»nton trap ^**
Griggstown copper mine 136-139
H.
Haelig, Wm., trap rock tests 172
Hardness of road metal, 166
trap rock, 171
Page
Hartshorn, Stewart, trap rock tests,... 172
Hibemia mines, 176
Hibemia, test of stone from, 46
Hoffman copper mine, 250
Hoff mine, 175, 176
Hook Mountain 109
Hosier, Helmer, trap rock tests 171
Hude mine 175, 176
Hudson river, fault along, 128
Hunt, N. H., white limestone of, 177
Hurd mine, 176
Hydrocuprite, 247
Hydrothermal origin of copper ores,.. x6o
I.
Ilmenite in glass sand ; '89, 91, 95
Intrusive trap sheets, origin of, 125
origin of copper
ores in, x6o
Iron, effects of, in glass sand 92
mines, list of active X75
report on za
ore, production of, 175, 179
J.
Jamesburg, glass sand near, 8x
Jenny Jump Mountain, X5
Jersey City Water Supply Company,
test of stone from 36
K.
Kice, Lyman, test of stone from, 32
Knapp, G. N., X3
Ktimmel, H. B., reports by x, 79, X73
Lambertville, test of stone from,... 52, 171
Lava flows, X13
Lava, pressure of, 126
Leonard shaft, . .*. 17^
Leucoxene in glass sand 89, 91
Lewis, J. Volney xo, 97, 165
Library, 6
Liththipe & Son, trap rock tests, X71
Limestone, 8
industry I77
test of, 24, 30, 70, 73, 74
white, composition of, X78
production of, i77
uses of, X78
Long Hill 109, X25
Lubey, P., test of stone from 48
M.
Malachite, ^3Sf
X36, X38, X42, 14s. X47. isx, 153
INDEX.
191
Page
Maps, new topographical 9
sheets published, 4
sheets sold 5
Margerum Bros., tests of stone from,. 7&
Marley, F. J., trap rock tests, 171
Martinsville, copper near, 151
test of stone from, 60
Maurer station, wells at, 118
Maurice river, glass sand near, 8z
McCourt, W. E., 10, 17
McKieman & Bergen, trap tests from,. 171
Menlo Park copper mine, 153
origin of ore at, 163
Millington Crushed Stone Company,
trap rock tests, 171
Millville, glass sand near, 8z
Mineral statistics, 179
Mineral waters, 12
Mining industry, 173
Montville, tests of stone from, 36
Morristown, tests of stone from, 48
Mount Arlington, tests of stone from, 42
Mount Gilboa, X20
Mount Hope mines 176
N.
Nason, Frank t,-, 8
Newark rocks, arid climate, 108
character of, loi
conditions of origin, ... 103
deformation of, 127
erosion of 127
estuarine, origin of, ... J03
extent of 99
lake deposits 104
origin of, 99
Piedmont plain, origin
of, Z06
river origin of, 105
sources of, loi
thickness of, 107
tilting of, 107
New Brunswick, copper near, 151
origin of ore at, .... 163
trap near, 119
New Germantown, trap near, 115
New Jersey Lime Company, limestone, 177
New Jersey Stone Company, tests of
stone from, 34
Newton, test of stone from, 72
Newtown, copper near 155
origin of copper near, 163
silver near, 155
New Vernon trap ridges, no
Nicoll & Co., test of stone from, 70
white limestone from, .. 177
North Arlington, test of stone from, . . 66
North Jersey Stone Co., test of stone
from, 42, 44
o.
Page
O'Donnell & McManniman, test of
stone from, 72
O'Neill & Hopkins, trap rock tests, ... 271
O'Rourke, John, trap rock tests, 171
Osborne & Marcellis, trap rock tests,.. 171
P.
Packanack Mountain 109
Page, L. W., quoted, 166
Paleobotany, work in, z6
Paleontology, work in, 15
Paleozoic work 14
Palisades, 17
Palisades, offshoots from, 121
relations to shales, 120
Panther Hill Granite Co., test of stone
from, 34
Parmelee, C. W., xo
Paterson Crushed Stone Co., trap tests, 171
Peat, report on, zo
Pennington Mountain, copper on, Z55
trap near, z20
Perth Amboy, wells at, z z8
Phillipsburg, test of stone from 74
Plainfield, copper mine near, Z50
origin of copper ore 162
test of stone from, 50
Pleasantdale, test of stone from 62
Pleistocene work ' 23
Pluckemin, copper mines near 250
Pompton Junction, test of stone from, 38
Potter, A. A., trap rock tests, 272
Pressure of Newark sediments, 226
Princeton, test of stone from 76
Publications, 4, 283
Pyroxene, copper in, 234
R.
Raritan mine, 2 52
Raven Rock, test of stone from, ../... 58
Reports, distribution of 6
published, 4
Richard mine, '276
Riker Hill 109
Road metal, qualities of, 266
Rocky Hill, 227
copper mine at, 236
Round Mountain trap, 222
Rutile in glass sand 89, 92
8.
St. Louis Exposition, medals from, .... 26
Sand Brook trap sheet 225
Sandstones, tests of,
24, 29, 54, 56, 58, 60, 62, 64, 66, 68
Schuyler mine, 240, 242, 243
Scrub Oak mine, 276
